diff --git a/.github/snippet-bot.yml b/.github/snippet-bot.yml
new file mode 100644
index 0000000000..51d12e4120
--- /dev/null
+++ b/.github/snippet-bot.yml
@@ -0,0 +1,2 @@
+aggregateChecks: false
+alwaysCreateStatusCheck: false
\ No newline at end of file
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 1b5b979aaf..dbf5754794 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -49,7 +49,7 @@ jobs:
         run: bazel --batch test $(bazel query "//src/test/..." | grep "Test$") --noshow_progress --test_output=errors
 
       - name: Integration Tests
-        run: bazel --batch test //test/integration:asset //test/integration:credentials //test/integration:iam //test/integration:kms //test/integration:logging //test/integration:pubsub //test/integration:redis //test/integration:library --noshow_progress
+        run: bazel --batch test //test/integration/...
 
       - uses: actions/upload-artifact@v2
         if: ${{ failure() }}
diff --git a/BUILD.bazel b/BUILD.bazel
index 8823250fca..913c6d063a 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -8,14 +8,17 @@ load(
 package(default_visibility = ["//visibility:public"])
 
 JAVA_SRCS = [
+    "//src/main/java/com/google/api/generator/debug:debug_files",
     "//src/main/java/com/google/api/generator:generator_files",
     "//src/main/java/com/google/api/generator/engine:engine_files",
     "//src/main/java/com/google/api/generator/gapic:gapic_files",
+    "//src/main/java/com/google/api/generator/util:util_files",
 ]
 
 TEST_SRCS = [
     "//src/test/java/com/google/api/generator/engine:engine_files",
     "//src/test/java/com/google/api/generator/gapic:gapic_files",
+    "//src/test/java/com/google/api/generator/testutils:testutils_files",
     "//src/test/java/com/google/api/generator/util:util_files",
     "//src/test/java/com/google/api/generator/test/framework:framework_files",
 ]
@@ -45,6 +48,57 @@ java_binary(
     ],
 )
 
+# Request dumper binary, which dumps the CodeGeneratorRequest to a file on disk
+# which will be identical to the one passed to the protoc-gen-java_gapic during
+# normal execution. The dumped file then can be used to run this gapic-generator
+# directly (instead of relying on protoc to start the process), which would give
+# much greater flexibility in terms of debugging features, like attaching a
+# debugger, easier work with stdout and stderr etc.
+#
+# Usage example, via the rule in a corresponding BUILD.bazel file:
+#
+# load("@gapic_generator_java//rules_java_gapic:java_gapic.bzl", "java_generator_request_dump")
+# java_generator_request_dump(
+#     name = "compute_small_request_dump",
+#     srcs = [":compute_small_proto_with_info"],
+#     transport = "rest",
+# )
+#
+java_binary(
+    name = "protoc-gen-code_generator_request_dumper",
+    main_class = "com.google.api.generator.debug.CodeGeneratorRequestDumper",
+    runtime_deps = [
+        "//src/main/java/com/google/api/generator",
+        "//src/main/java/com/google/api/generator/debug",
+        "//src/main/java/com/google/api/generator/gapic",
+        "@com_google_googleapis//google/api:api_java_proto",
+        "@com_google_googleapis//google/longrunning:longrunning_java_proto",
+        "@com_google_guava_guava",
+        "@com_google_protobuf//:protobuf_java",
+    ],
+)
+
+# A binary similar to protoc-gen-java_gapic but reads the CodeGeneratorRequest
+# directly from a file instead of relying on protoc to pipe it in.
+#
+# Usage example:
+#
+# bazel run code_generator_request_file_to_gapic_main desc-dump.bin dump.jar
+#
+java_binary(
+    name = "code_generator_request_file_to_gapic_main",
+    main_class = "com.google.api.generator.debug.CodeGeneratorRequestFileToGapicMain",
+    runtime_deps = [
+        "//src/main/java/com/google/api/generator",
+        "//src/main/java/com/google/api/generator/debug",
+        "//src/main/java/com/google/api/generator/gapic",
+        "@com_google_googleapis//google/api:api_java_proto",
+        "@com_google_googleapis//google/longrunning:longrunning_java_proto",
+        "@com_google_guava_guava",
+        "@com_google_protobuf//:protobuf_java",
+    ],
+)
+
 # google-java-format
 java_binary(
     name = "google_java_format_binary",
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 03abe4a067..47548ec096 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,131 @@
 # Changelog
 
+## [2.1.0](https://www.github.com/googleapis/gapic-generator-java/compare/v2.0.1...v2.1.0) (2021-08-17)
+
+
+### Features
+
+* enable self signed jwt for gapic clients ([#794](https://www.github.com/googleapis/gapic-generator-java/issues/794)) ([1b7ee1e](https://www.github.com/googleapis/gapic-generator-java/commit/1b7ee1e3911e1c8ecab9a94d68d7a59b437d2449))
+
+### [2.0.1](https://www.github.com/googleapis/gapic-generator-java/compare/v2.0.0...v2.0.1) (2021-08-06)
+
+
+### Bug Fixes
+
+* bring back unused resnames for Ads ([#821](https://www.github.com/googleapis/gapic-generator-java/issues/821)) ([7fa135c](https://www.github.com/googleapis/gapic-generator-java/commit/7fa135c9aa60c9cb15880e098d36ea81b95ea488))
+* **resnames:** ensure deterministic resname order for samplegen ([#813](https://www.github.com/googleapis/gapic-generator-java/issues/813)) ([c4709df](https://www.github.com/googleapis/gapic-generator-java/commit/c4709df5d8ed9f0074f7e25df5db93e9d9b35749))
+
+## [2.0.0](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.17...v2.0.0) (2021-08-03)
+
+
+### ⚠ BREAKING CHANGES
+
+* remove Exception, unused resname classes for Java major version bump (#814)
+
+### Features
+
+* Lambda-ize single-method anon classes (Java 8+) ([#815](https://www.github.com/googleapis/gapic-generator-java/issues/815)) ([19b661c](https://www.github.com/googleapis/gapic-generator-java/commit/19b661cc78757e37ce93bae96eb81cb4ac32658b))
+* remove Exception, unused resname classes for Java major version bump ([#814](https://www.github.com/googleapis/gapic-generator-java/issues/814)) ([8abece2](https://www.github.com/googleapis/gapic-generator-java/commit/8abece20dd20e9ac8134df04301ce5b6e2ab76ad))
+
+### [1.0.17](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.16...v1.0.17) (2021-08-02)
+
+
+### Features
+
+* **ast:** Add support for multi-catch blocks [ggj] ([#811](https://www.github.com/googleapis/gapic-generator-java/issues/811)) ([55ef1a6](https://www.github.com/googleapis/gapic-generator-java/commit/55ef1a63427683538e48050333eedb0666635568))
+* **ast:** Add support for Throwable causes [ggj] ([#801](https://www.github.com/googleapis/gapic-generator-java/issues/801)) ([7fdeece](https://www.github.com/googleapis/gapic-generator-java/commit/7fdeeced7642fefdfdc5c6e898661c72fe9d78a8))
+* **ast:** support throwing all kinds of expressions ([#810](https://www.github.com/googleapis/gapic-generator-java/issues/810)) ([0817650](https://www.github.com/googleapis/gapic-generator-java/commit/0817650b35487f32d7987ba718ce71fc7551e3a0))
+
+
+### Bug Fixes
+
+* (rest transport) Add `@BetaApi` to the generated `TransportServiceFactory` class and lro-specific method ([#787](https://www.github.com/googleapis/gapic-generator-java/issues/787)) ([ebe1aef](https://www.github.com/googleapis/gapic-generator-java/commit/ebe1aefbe860a41aabd8ced5268ccc6c7efdf791))
+* prevent hanging by call backgroundResources.close() on stub.close() [ggj] ([#804](https://www.github.com/googleapis/gapic-generator-java/issues/804)) ([428db97](https://www.github.com/googleapis/gapic-generator-java/commit/428db97c1534255a60530a8ed6137efc17ed56f4))
+* **resnames:** fallback to fully-qualified Object name upon proto typing conflicts [ggj] ([#803](https://www.github.com/googleapis/gapic-generator-java/issues/803)) ([e654bfb](https://www.github.com/googleapis/gapic-generator-java/commit/e654bfb936b571af2546f550c9a1589f8ad63d67))
+
+
+
+### [1.0.16](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.15...v1.0.16) (2021-06-30)
+
+
+### Bug Fixes
+
+* **bazel:** Eradicate monolith deps from Java µgen repo ([#778](https://www.github.com/googleapis/gapic-generator-java/issues/778)) ([86f2472](https://www.github.com/googleapis/gapic-generator-java/commit/86f2472963f020127ef6ff92be6241d12e2273af))
+* **build:** Update googleapis-discovery hash to fix compute integration test ([#782](https://www.github.com/googleapis/gapic-generator-java/issues/782)) ([46bb19a](https://www.github.com/googleapis/gapic-generator-java/commit/46bb19a7ee61da86b4be6d87a71f3cd210e753d2))
+* **protoc:** Mirror protoc's field name conflict resolution logic in client generation ([#781](https://www.github.com/googleapis/gapic-generator-java/issues/781)) ([9432979](https://www.github.com/googleapis/gapic-generator-java/commit/9432979bab59f48c8645fa47d752cdd470d4a682))
+
+### [1.0.15](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.14...v1.0.15) (2021-06-22)
+
+
+### Features
+
+* Implement field presence support for DIREGAPIC ([#774](https://www.github.com/googleapis/gapic-generator-java/issues/774)) ([c820361](https://www.github.com/googleapis/gapic-generator-java/commit/c82036105d299b0a1192cd0def5e68253e4f542c))
+
+
+### Bug Fixes
+
+* **service.yaml:** Remove allowlist restriction ([#776](https://www.github.com/googleapis/gapic-generator-java/issues/776)) ([8f42efd](https://www.github.com/googleapis/gapic-generator-java/commit/8f42efdb92d606a768a524517fe949c4f9112025))
+
+
+### Miscellaneous Chores
+
+* release 1.0.15 ([f752478](https://www.github.com/googleapis/gapic-generator-java/commit/f75247845344540a94c4efcd416f34f96ea0c2a3))
+
+### [1.0.14](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.13...v1.0.14) (2021-06-17)
+
+
+### Features
+
+* Add DIREGAPIC-specific pagination ([#767](https://www.github.com/googleapis/gapic-generator-java/issues/767)) ([1294c29](https://www.github.com/googleapis/gapic-generator-java/commit/1294c298f50cc4474ae562e6a07f37a5f94fe5b8))
+
+
+### Bug Fixes
+
+* **bazel:** Remove monolith rule deps from the Java µgen Bazel rules ([#764](https://www.github.com/googleapis/gapic-generator-java/issues/764)) ([bff3efc](https://www.github.com/googleapis/gapic-generator-java/commit/bff3efc25e43692ea5b6e769c20d25d5b9a1e3d2))
+
+
+
+### [1.0.13](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.12...v1.0.13) (2021-06-16)
+
+
+### Bug Fixes
+
+* **resnames:** Fix resname builder name conflicts in ctor with this assignment ([#769](https://www.github.com/googleapis/gapic-generator-java/issues/769)) ([edac844](https://www.github.com/googleapis/gapic-generator-java/commit/edac8447d74c43ab0db963a37f66e1029ab19f0c))
+
+### [1.0.12](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.11...v1.0.12) (2021-06-10)
+
+
+### Features
+
+* add mtls support ([#672](https://www.github.com/googleapis/gapic-generator-java/issues/672)) ([1e24893](https://www.github.com/googleapis/gapic-generator-java/commit/1e24893a65daf8ef067e331364c591ac973b5e02))
+
+
+### Bug Fixes
+
+* **mocks:** Use java.lang.Object if there are protos named 'Object' ([#760](https://www.github.com/googleapis/gapic-generator-java/issues/760)) ([2a7064b](https://www.github.com/googleapis/gapic-generator-java/commit/2a7064b88fe26586bd8aed43b7a7d28c7e974ec0))
+* **resnames:** Use anon resname classes when only wildcards are present ([#763](https://www.github.com/googleapis/gapic-generator-java/issues/763)) ([f0ecead](https://www.github.com/googleapis/gapic-generator-java/commit/f0ecead9f1cc645cdbb7f61cdfc820c7df95355d))
+
+
+### Miscellaneous Chores
+
+* release 1.0.12 ([02eab0e](https://www.github.com/googleapis/gapic-generator-java/commit/02eab0ec61260048a2684119cfd4fa2172f3a637))
+
+### [1.0.11](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.10...v1.0.11) (2021-06-07)
+
+
+### Features
+
+* DIREGAPIC initial implementation ([#746](https://www.github.com/googleapis/gapic-generator-java/issues/746)) ([81f6737](https://www.github.com/googleapis/gapic-generator-java/commit/81f6737359ac6ce5ee2b42ab4f755fbb05a3cf28))
+
+
+### Bug Fixes
+
+* **bazel:** ensure integration tests diff files recursively ([#745](https://www.github.com/googleapis/gapic-generator-java/issues/745)) ([ddc75f9](https://www.github.com/googleapis/gapic-generator-java/commit/ddc75f9f3b84d0ea50638a79a63d40cf551211e2))
+* **resnames:** filter out mixin services from resname pkg candidates ([#751](https://www.github.com/googleapis/gapic-generator-java/issues/751)) ([72fa76f](https://www.github.com/googleapis/gapic-generator-java/commit/72fa76f27379a74a143b1735f60ae3e00da4c1a6))
+* **tests:** Ensure deterministic field ordering in test classes ([#743](https://www.github.com/googleapis/gapic-generator-java/issues/743)) ([fdb705b](https://www.github.com/googleapis/gapic-generator-java/commit/fdb705b0a39443fb0b7679d879f27e0aa1c36b67))
+* **tests:** handle Java 11 set ordering differences for RPCs and fields in test/mock classes ([#750](https://www.github.com/googleapis/gapic-generator-java/issues/750)) ([eaf4592](https://www.github.com/googleapis/gapic-generator-java/commit/eaf4592e139fbc42810e7f60dc9967320195bf85))
+
+
 ### [1.0.10](https://www.github.com/googleapis/gapic-generator-java/compare/v1.0.9...v1.0.10) (2021-05-26)
 
 
diff --git a/DEVELOPMENT.md b/DEVELOPMENT.md
index 144b904963..ce5fec73c5 100644
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -15,17 +15,17 @@
 ## Running the Plugin
 
 1.  Clone [googleapis](https://github.com/googleapis/googleapis) and
-    [gapic-showcase](https://github.com/googleapis/gapic-showcase/) and install
-    protoc.
+    [gapic-showcase](https://github.com/googleapis/gapic-showcase/).
 
 2.  Copy the protos from Showcase into googleapis/google/showcase.
 
     ```sh
-    cp gapic-showcase/schema/google/showcase/v1beta1 googleapis/google/showcase/v1beta
+    mkdir googleapis/google/showcase
+    cp -r gapic-showcase/schema/google/showcase/v1beta1 googleapis/google/showcase/v1beta1
     ```
 
-3.  Add the new microgenerator rules to the protobuf directory's `BUILD.bazel`
-    file as follows:
+3.  Add the new microgenerator rules to
+    `googleapis/google/showcase/v1beta1/BUILD.bazel` file as follows:
 
     ```python
     load(
@@ -33,6 +33,22 @@
         # Existing rules here.
         "java_gapic_assembly_gradle_pkg",
         "java_gapic_library",
+        "java_proto_library",
+        "proto_library_with_info",
+    )
+
+    proto_library_with_info(
+        name = "showcase_proto_with_info",
+        deps = [
+            ":showcase_proto",
+        ],
+    )
+
+    java_proto_library(
+        name = "showcase_java_proto",
+        deps = [
+            "showcase_proto",
+        ],
     )
 
     # This should either replace the existing monolith target or have a unique name
@@ -97,13 +113,6 @@
     bazel run //src/test/java/com/google/api/generator/engine:JavaCodeGeneratorTest
     ```
 
--   Update goldens files based on code generation in unit test, for example
-    `JavaCodeGeneratorTest.java`
-
-    ```sh
-    bazel run //src/test/java/com/google/api/generator/engine:JavaCodeGeneratorTest_update
-    ```
-
 -   Run a single integration test for API like `Redis`, it generates Java source
     code using the Java microgenerator and compares them with the goldens files
     in `test/integration/goldens/redis`.
@@ -112,10 +121,20 @@
     bazel test //test/integration:redis
     ```
 
--   Update goldens files based on code generation in integration test, for
-    example `Redis`. It generates Java source code using the Java microgenerator
-    and overwrites the goldens files in `test/integration/goldens/redis` based
-    on code generation.
+-   Run all unit and integration tests.
+
+    ```sh
+    bazel test $(bazel query "src/test/..." | grep "Test$") //test/integration/...
+    ```
+
+-   Update unit test golden files, for example `JavaCodeGeneratorTest.java`:
+
+    ```sh
+    bazel run //src/test/java/com/google/api/generator/engine:JavaCodeGeneratorTest_update
+    ```
+
+-   Update integration test golden files, for example `Redis`. This clobbers all the
+    files in `test/integration/goldens/redis`.
 
     ```sh
     bazel run //test/integration:redis_update
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000000..8b58ae9c01
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,7 @@
+# Security Policy
+
+To report a security issue, please use [g.co/vulnz](https://g.co/vulnz).
+
+The Google Security Team will respond within 5 working days of your report on g.co/vulnz.
+
+We use g.co/vulnz for our intake, and do coordination and disclosure here using GitHub Security Advisory to privately discuss and fix the issue.
diff --git a/WORKSPACE b/WORKSPACE
index 66982c622d..21e5f8ea67 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1,6 +1,7 @@
 workspace(name = "gapic_generator_java")
 
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+load("@bazel_tools//tools/build_defs/repo:jvm.bzl", "jvm_maven_import_external")
 
 # DO NOT REMOVE.
 # This is needed to clobber any transitively-pulled in versions of bazel_skylib so that packages
@@ -14,6 +15,42 @@ http_archive(
     ],
 )
 
+jvm_maven_import_external(
+    name = "google_java_format_all_deps",
+    artifact = "com.google.googlejavaformat:google-java-format:jar:all-deps:1.7",
+    licenses = [
+        "notice",
+        "reciprocal",
+    ],
+    server_urls = [
+        "https://repo.maven.apache.org/maven2/",
+        "http://repo1.maven.org/maven2/",
+    ],
+)
+
+# gax-java and its transitive dependencies must be imported before
+# gapic-generator-java dependencies to match the order in googleapis repository,
+# which in its turn, prioritizes actual generated clients runtime dependencies
+# over the generator dependencies.
+_gax_java_version = "2.3.0"
+
+http_archive(
+    name = "com_google_api_gax_java",
+    strip_prefix = "gax-java-%s" % _gax_java_version,
+    urls = ["https://github.com/googleapis/gax-java/archive/v%s.zip" % _gax_java_version],
+)
+
+load("@com_google_api_gax_java//:repository_rules.bzl", "com_google_api_gax_java_properties")
+
+com_google_api_gax_java_properties(
+    name = "com_google_api_gax_java_properties",
+    file = "@com_google_api_gax_java//:dependencies.properties",
+)
+
+load("@com_google_api_gax_java//:repositories.bzl", "com_google_api_gax_java_repositories")
+
+com_google_api_gax_java_repositories()
+
 load("//:repository_rules.bzl", "gapic_generator_java_properties")
 
 gapic_generator_java_properties(
@@ -31,14 +68,16 @@ load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
 
 protobuf_deps()
 
-# Java dependencies.
-# Import the monolith so we can transitively use its gapic rules for googleapis.
+# Bazel rules.
+_rules_gapic_version = "0.5.5"
+
 http_archive(
-    name = "com_google_api_codegen",
-    strip_prefix = "gapic-generator-2.4.6",
-    urls = ["https://github.com/googleapis/gapic-generator/archive/v2.4.6.zip"],
+    name = "rules_gapic",
+    strip_prefix = "rules_gapic-%s" % _rules_gapic_version,
+    urls = ["https://github.com/googleapis/rules_gapic/archive/v%s.tar.gz" % _rules_gapic_version],
 )
 
+# Java dependencies.
 load("@com_google_googleapis//:repository_rules.bzl", "switched_rules_by_language")
 
 switched_rules_by_language(
@@ -48,25 +87,12 @@ switched_rules_by_language(
     java = True,
 )
 
-_gax_java_version = PROPERTIES["version.com_google_gax_java"]
-
-http_archive(
-    name = "com_google_api_gax_java",
-    strip_prefix = "gax-java-%s" % _gax_java_version,
-    urls = ["https://github.com/googleapis/gax-java/archive/v%s.zip" % _gax_java_version],
-)
-
-load("@com_google_api_gax_java//:repository_rules.bzl", "com_google_api_gax_java_properties")
-
-com_google_api_gax_java_properties(
-    name = "com_google_api_gax_java_properties",
-    file = "@com_google_api_gax_java//:dependencies.properties",
-)
-
-load("@com_google_api_gax_java//:repositories.bzl", "com_google_api_gax_java_repositories")
-
-com_google_api_gax_java_repositories()
-
 load("@io_grpc_grpc_java//:repositories.bzl", "grpc_java_repositories")
 
 grpc_java_repositories()
+
+http_archive(
+    name = "com_google_disco_to_proto3_converter",
+    strip_prefix = "disco-to-proto3-converter-4b0956884b1aa9b367cf41488b622dc12eb16652",
+    urls = ["https://github.com/googleapis/disco-to-proto3-converter/archive/4b0956884b1aa9b367cf41488b622dc12eb16652.zip"],
+)
diff --git a/dependencies.properties b/dependencies.properties
index 841111924b..75e53a6461 100644
--- a/dependencies.properties
+++ b/dependencies.properties
@@ -4,14 +4,13 @@
 # The properties format is the following:
 #   <dependency_type>[.<artifact_name>]=<value>
 
-# Target workspace name: com_google_api_codegen
+# Target workspace name: gapic_generator_java
 
 # Versions only, for dependencies which actual artifacts differ between Bazel and Gradle
-version.com_google_protobuf=3.13.0
+version.com_google_protobuf=3.15.8
 # Version of google-java-format is downgraded from 1.8 to 1.7, because 1.8 supports java 11 minimum, while our JRE is java 8.
 version.google_java_format=1.7
 version.com_google_api_common_java=1.9.3
-version.com_google_gax_java=1.62.0
 version.io_grpc_java=1.30.2
 
 # Common deps.
@@ -20,7 +19,7 @@ maven.com_google_code_findbugs_jsr305=com.google.code.findbugs:jsr305:3.0.0
 maven.com_google_auto_value_auto_value=com.google.auto.value:auto-value:1.7.2
 maven.com_google_auto_value_auto_value_annotations=com.google.auto.value:auto-value-annotations:1.7.2
 maven.com_google_code_gson=com.google.code.gson:gson:2.8.6
-maven.com_google_protobuf_protobuf_java=com.google.protobuf:protobuf-java:3.12.2
+maven.com_google_protobuf_protobuf_java=com.google.protobuf:protobuf-java:3.15.8
 maven.io_github_java_diff_utils=io.github.java-diff-utils:java-diff-utils:4.0
 maven.javax_annotation_javax_annotation_api=javax.annotation:javax.annotation-api:1.3.2
 maven.javax_validation_javax_validation_api=javax.validation:validation-api:2.0.1.Final
@@ -33,7 +32,7 @@ maven.org_threeten_threetenbp=org.threeten:threetenbp:1.3.3
 
 # Testing.
 maven.junit_junit=junit:junit:4.13.1
-# This hamcrest-core dependency is for running JUnit test manually, before JUnit 4.11 it's wrapped along with JUnit package. 
+# This hamcrest-core dependency is for running JUnit test manually, before JUnit 4.11 it's wrapped along with JUnit package.
 # But now it has to be explicitly added.
 maven.org_hamcrest_hamcrest_core=org.hamcrest:hamcrest-core:1.3
 maven.org_mockito_mockito_core=org.mockito:mockito-core:2.21.0
diff --git a/repositories.bzl b/repositories.bzl
index e246cef5cc..67493dba45 100644
--- a/repositories.bzl
+++ b/repositories.bzl
@@ -59,9 +59,18 @@ def gapic_generator_java_repositories():
     _maybe(
         http_archive,
         name = "com_google_googleapis",
-        strip_prefix = "googleapis-2bea43cdc7a4443876380732980d83cd8d560582",
+        strip_prefix = "googleapis-efecdbf96311bb705d619459280ffc651b10844a",
         urls = [
-            "https://github.com/googleapis/googleapis/archive/2bea43cdc7a4443876380732980d83cd8d560582.zip",
+            "https://github.com/googleapis/googleapis/archive/efecdbf96311bb705d619459280ffc651b10844a.zip",
+        ],
+    )
+
+    _maybe(
+        http_archive,
+        name = "com_google_googleapis_discovery",
+        strip_prefix = "googleapis-discovery-abf4cec1ce9e02e4d7d650bf66137c347cdd0d44",
+        urls = [
+            "https://github.com/googleapis/googleapis-discovery/archive/abf4cec1ce9e02e4d7d650bf66137c347cdd0d44.zip",
         ],
     )
 
diff --git a/rules_bazel/java/integration_test.bzl b/rules_bazel/java/integration_test.bzl
index ae07c422aa..e030b5f817 100644
--- a/rules_bazel/java/integration_test.bzl
+++ b/rules_bazel/java/integration_test.bzl
@@ -23,7 +23,7 @@ def _diff_integration_goldens_impl(ctx):
     rm -rf $(find ./ -type f -name 'PlaceholderFile.java')
     rm -r $(find ./ -type d -empty)
     cd ..
-    diff codegen_tmp test/integration/goldens/{api_name}/ > {diff_output}
+    diff -r codegen_tmp test/integration/goldens/{api_name} > {diff_output}
     # Bash `diff` command will return exit code 1 when there are differences between the two
     # folders. So we explicitly `exit 0` after the diff command to avoid build failure.
     exit 0
diff --git a/rules_java_gapic/java_gapic.bzl b/rules_java_gapic/java_gapic.bzl
index 9c2436174c..91eb4ddb56 100644
--- a/rules_java_gapic/java_gapic.bzl
+++ b/rules_java_gapic/java_gapic.bzl
@@ -12,9 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-load("@com_google_api_codegen//rules_gapic:gapic.bzl", "proto_custom_library", "unzipped_srcjar")
+load("@rules_gapic//:gapic.bzl", "proto_custom_library", "unzipped_srcjar")
 
-SERVICE_YAML_ALLOWLIST = ["clouddms", "cloudkms", "datastream", "pubsub"]
 NO_GRPC_CONFIG_ALLOWLIST = ["library"]
 
 def _java_gapic_postprocess_srcjar_impl(ctx):
@@ -119,20 +118,24 @@ def _append_dep_without_duplicates(dest_deps, new_deps):
             dest_deps.append(new_deps[i])
     return dest_deps
 
-def java_gapic_library(
+def _java_gapic_srcjar(
         name,
         srcs,
-        grpc_service_config = None,
-        gapic_yaml = None,
-        service_yaml = None,
-        deps = [],
-        test_deps = [],
+        grpc_service_config,
+        gapic_yaml,
+        service_yaml,
+        # possible values are: "grpc", "rest", "grpc+rest"
+        transport,
+        # Can be used to provide a java_library with a customized generator,
+        # like the one which dumps descriptor to a file for future debugging.
+        java_generator_name = "java_gapic",
+        output_suffix = ".srcjar",
         **kwargs):
     file_args_dict = {}
 
     if grpc_service_config:
         file_args_dict[grpc_service_config] = "grpc-service-config"
-    else:
+    elif not transport or transport == "grpc":
         for keyword in NO_GRPC_CONFIG_ALLOWLIST:
             if keyword not in name:
                 fail("Missing a gRPC service config file")
@@ -140,38 +143,54 @@ def java_gapic_library(
     if gapic_yaml:
         file_args_dict[gapic_yaml] = "gapic-config"
 
-    # Check the allow-list.
-    # TODO: Open this up after mixins are published, and gate on
-    # the allowlisted "mixed-in" APIs present in Java.
     if service_yaml:
-        service_yaml_in_allowlist = False
-        for keyword in SERVICE_YAML_ALLOWLIST:
-            if keyword in service_yaml:
-                service_yaml_in_allowlist = True
-                break
-        if service_yaml_in_allowlist:
-            file_args_dict[service_yaml] = "api-service-config"
-        else:
-            fail("Service.yaml is no longer supported in the Java microgenerator")
+        file_args_dict[service_yaml] = "api-service-config"
 
-    srcjar_name = name + "_srcjar"
-    raw_srcjar_name = srcjar_name + "_raw"
     output_suffix = ".srcjar"
+    opt_args = []
+
+    if transport:
+        opt_args.append("transport=%s" % transport)
 
     # Produces the GAPIC metadata file if this flag is set. to any value.
     # Protoc invocation: --java_gapic_opt=metadata
     plugin_args = ["metadata"]
 
-    _java_generator_name = "java_gapic"
     proto_custom_library(
-        name = raw_srcjar_name,
+        name = name,
         deps = srcs,
-        plugin = Label("@gapic_generator_java//:protoc-gen-%s" % _java_generator_name),
+        plugin = Label("@gapic_generator_java//:protoc-gen-%s" % java_generator_name),
         plugin_args = plugin_args,
         plugin_file_args = {},
         opt_file_args = file_args_dict,
-        output_type = _java_generator_name,
+        output_type = java_generator_name,
         output_suffix = output_suffix,
+        opt_args = opt_args,
+        **kwargs
+    )
+
+def java_gapic_library(
+        name,
+        srcs,
+        grpc_service_config = None,
+        gapic_yaml = None,
+        service_yaml = None,
+        deps = [],
+        test_deps = [],
+        # possible values are: "grpc", "rest", "grpc+rest"
+        transport = None,
+        **kwargs):
+    srcjar_name = name + "_srcjar"
+    raw_srcjar_name = srcjar_name + "_raw"
+
+    _java_gapic_srcjar(
+        name = raw_srcjar_name,
+        srcs = srcs,
+        grpc_service_config = grpc_service_config,
+        gapic_yaml = gapic_yaml,
+        service_yaml = service_yaml,
+        transport = transport,
+        java_generator_name = "java_gapic",
         **kwargs
     )
 
@@ -201,10 +220,7 @@ def java_gapic_library(
         "@com_google_protobuf//:protobuf_java",
         "@com_google_api_api_common//jar",
         "@com_google_api_gax_java//gax:gax",
-        "@com_google_api_gax_java//gax-grpc:gax_grpc",
         "@com_google_guava_guava//jar",
-        "@io_grpc_grpc_java//core:core",
-        "@io_grpc_grpc_java//protobuf:protobuf",
         "@com_google_code_findbugs_jsr305//jar",
         "@org_threeten_threetenbp//jar",
         "@io_opencensus_opencensus_api//jar",
@@ -214,6 +230,26 @@ def java_gapic_library(
         "@javax_annotation_javax_annotation_api//jar",
     ]
 
+    if not transport or transport == "grpc":
+        actual_deps += [
+            "@com_google_api_gax_java//gax-grpc:gax_grpc",
+            "@io_grpc_grpc_java//core:core",
+            "@io_grpc_grpc_java//protobuf:protobuf",
+        ]
+    elif transport == "rest":
+        actual_deps += [
+            "@com_google_api_gax_java//gax-httpjson:gax_httpjson",
+        ]
+    elif transport == "grpc+rest":
+        actual_deps += [
+            "@com_google_api_gax_java//gax-grpc:gax_grpc",
+            "@io_grpc_grpc_java//core:core",
+            "@io_grpc_grpc_java//protobuf:protobuf",
+            "@com_google_api_gax_java//gax-httpjson:gax_httpjson",
+        ]
+    else:
+        fail("Unknown transport: %s" % transport)
+
     native.java_library(
         name = name,
         srcs = ["%s.srcjar" % srcjar_name],
@@ -224,15 +260,35 @@ def java_gapic_library(
     # Test deps.
     actual_test_deps = [
         "@com_google_googleapis//google/type:type_java_proto",  # Commonly used.
-        "@com_google_api_gax_java//gax-grpc:gax_grpc_testlib",
         "@com_google_api_gax_java//gax:gax_testlib",
         "@com_google_code_gson_gson//jar",
-        "@io_grpc_grpc_java//auth:auth",
-        "@io_grpc_grpc_netty_shaded//jar",
-        "@io_grpc_grpc_java//stub:stub",
-        "@io_opencensus_opencensus_contrib_grpc_metrics//jar",
         "@junit_junit//jar",
     ]
+
+    if not transport or transport == "grpc":
+        actual_test_deps += [
+            "@com_google_api_gax_java//gax-grpc:gax_grpc_testlib",
+            "@io_grpc_grpc_java//auth:auth",
+            "@io_grpc_grpc_netty_shaded//jar",
+            "@io_grpc_grpc_java//stub:stub",
+            "@io_opencensus_opencensus_contrib_grpc_metrics//jar",
+        ]
+    elif transport == "rest":
+        actual_test_deps += [
+            "@com_google_api_gax_java//gax-httpjson:gax_httpjson_testlib",
+        ]
+    elif transport == "grpc+rest":
+        actual_test_deps += [
+            "@com_google_api_gax_java//gax-grpc:gax_grpc_testlib",
+            "@io_grpc_grpc_java//auth:auth",
+            "@io_grpc_grpc_netty_shaded//jar",
+            "@io_grpc_grpc_java//stub:stub",
+            "@io_opencensus_opencensus_contrib_grpc_metrics//jar",
+            "@com_google_api_gax_java//gax-httpjson:gax_httpjson_testlib",
+        ]
+    else:
+        fail("Unknown transport: %s" % transport)
+
     _append_dep_without_duplicates(actual_test_deps, test_deps)
     _append_dep_without_duplicates(actual_test_deps, actual_deps)
 
@@ -256,3 +312,26 @@ def java_gapic_test(name, runtime_deps, test_classes, **kwargs):
         tests = test_classes,
         **kwargs
     )
+
+# A debugging rule, to dump CodeGenereatorRequest from protoc as is to a file,
+# which then can be used to run gapic-generator directly instead of relying on
+# protoc to launch it. This would simplify attaching the debugger and/or
+# working with stdin/stderr.
+def java_generator_request_dump(
+        name,
+        srcs,
+        grpc_service_config = None,
+        gapic_yaml = None,
+        service_yaml = None,
+        transport = None,
+        **kwargs):
+    _java_gapic_srcjar(
+        name = name,
+        srcs = srcs,
+        grpc_service_config = grpc_service_config,
+        gapic_yaml = gapic_yaml,
+        service_yaml = service_yaml,
+        transport = transport,
+        java_generator_name = "code_generator_request_dumper",
+        **kwargs
+    )
diff --git a/rules_java_gapic/java_gapic_pkg.bzl b/rules_java_gapic/java_gapic_pkg.bzl
index f06c515f72..eb109db524 100644
--- a/rules_java_gapic/java_gapic_pkg.bzl
+++ b/rules_java_gapic/java_gapic_pkg.bzl
@@ -301,6 +301,7 @@ def java_gapic_assembly_gradle_pkg(
         name,
         deps,
         assembly_name = None,
+        transport = None,
         **kwargs):
     package_dir = name
     if assembly_name:
@@ -350,9 +351,16 @@ def java_gapic_assembly_gradle_pkg(
         grpc_target_dep = ["%s" % grpc_target]
 
     if client_deps:
+        if not transport or transport == "grpc":
+            template_label = Label("//rules_java_gapic:resources/gradle/client_grpc.gradle.tmpl")
+        elif transport == "rest":
+            template_label = Label("//rules_java_gapic:resources/gradle/client_rest.gradle.tmpl")
+        elif transport == "grpc+rest":
+            template_label = Label("//rules_java_gapic:resources/gradle/client_grpcrest.gradle.tmpl")
+
         _java_gapic_gradle_pkg(
             name = client_target,
-            template_label = Label("//rules_java_gapic:resources/gradle/client.gradle.tmpl"),
+            template_label = template_label,
             deps = proto_target_dep + client_deps,
             test_deps = grpc_target_dep + client_test_deps,
             **kwargs
diff --git a/rules_java_gapic/resources/gradle/assembly.gradle.tmpl b/rules_java_gapic/resources/gradle/assembly.gradle.tmpl
index 3c0e59ee69..336a7a5c05 100644
--- a/rules_java_gapic/resources/gradle/assembly.gradle.tmpl
+++ b/rules_java_gapic/resources/gradle/assembly.gradle.tmpl
@@ -12,8 +12,8 @@ subprojects {
   apply plugin: 'java'
   apply plugin: 'maven'
 
-  sourceCompatibility = 1.7
-  targetCompatibility = 1.7
+  sourceCompatibility = 1.8
+  targetCompatibility = 1.8
 
   test {
     testLogging {
diff --git a/rules_java_gapic/resources/gradle/client.gradle.tmpl b/rules_java_gapic/resources/gradle/client_grpc.gradle.tmpl
similarity index 95%
rename from rules_java_gapic/resources/gradle/client.gradle.tmpl
rename to rules_java_gapic/resources/gradle/client_grpc.gradle.tmpl
index 137f38d6f2..5ed53f6401 100644
--- a/rules_java_gapic/resources/gradle/client.gradle.tmpl
+++ b/rules_java_gapic/resources/gradle/client_grpc.gradle.tmpl
@@ -9,8 +9,8 @@ apply plugin: 'java'
 description = 'GAPIC library for {{name}}'
 group = 'com.google.cloud'
 version = (findProperty('version') == 'unspecified') ? '0.0.0-SNAPSHOT' : version
-sourceCompatibility = 1.7
-targetCompatibility = 1.7
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
 
 repositories {
   mavenCentral()
diff --git a/rules_java_gapic/resources/gradle/client_grpcrest.gradle.tmpl b/rules_java_gapic/resources/gradle/client_grpcrest.gradle.tmpl
new file mode 100644
index 0000000000..fe5aa44622
--- /dev/null
+++ b/rules_java_gapic/resources/gradle/client_grpcrest.gradle.tmpl
@@ -0,0 +1,63 @@
+buildscript {
+  repositories {
+    mavenCentral()
+  }
+}
+
+apply plugin: 'java'
+
+description = 'GAPIC library for {{name}}'
+group = 'com.google.cloud'
+version = (findProperty('version') == 'unspecified') ? '0.0.0-SNAPSHOT' : version
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
+repositories {
+  mavenCentral()
+  mavenLocal()
+}
+
+compileJava.options.encoding = 'UTF-8'
+javadoc.options.encoding = 'UTF-8'
+
+dependencies {
+  compile 'com.google.api:gax:{{version.gax}}'
+  testCompile 'com.google.api:gax:{{version.gax}}:testlib'
+  compile 'com.google.api:gax-grpc:{{version.gax_grpc}}'
+  testCompile 'com.google.api:gax-grpc:{{version.gax_grpc}}:testlib'
+  compile 'com.google.api:gax-httpjson:{{version.gax_httpjson}}'
+  testCompile 'com.google.api:gax-httpjson:{{version.gax_httpjson}}:testlib'
+  testCompile 'io.grpc:grpc-netty-shaded:{{version.io_grpc}}'
+  testCompile '{{maven.junit_junit}}'
+  {{extra_deps}}
+}
+
+task smokeTest(type: Test) {
+  filter {
+    includeTestsMatching "*SmokeTest"
+    setFailOnNoMatchingTests false
+  }
+}
+
+test {
+  exclude "**/*SmokeTest*"
+}
+
+sourceSets {
+  main {
+    java {
+      srcDir 'src/main/java'
+    }
+  }
+}
+
+clean {
+  delete 'all-jars'
+}
+
+task allJars(type: Copy) {
+  dependsOn test, jar
+  into 'all-jars'
+  // Replace with `from configurations.testRuntime, jar` to include test dependencies
+  from configurations.runtime, jar
+}
diff --git a/rules_java_gapic/resources/gradle/client_rest.gradle.tmpl b/rules_java_gapic/resources/gradle/client_rest.gradle.tmpl
new file mode 100644
index 0000000000..20fab62963
--- /dev/null
+++ b/rules_java_gapic/resources/gradle/client_rest.gradle.tmpl
@@ -0,0 +1,60 @@
+buildscript {
+  repositories {
+    mavenCentral()
+  }
+}
+
+apply plugin: 'java'
+
+description = 'GAPIC library for {{name}}'
+group = 'com.google.cloud'
+version = (findProperty('version') == 'unspecified') ? '0.0.0-SNAPSHOT' : version
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
+repositories {
+  mavenCentral()
+  mavenLocal()
+}
+
+compileJava.options.encoding = 'UTF-8'
+javadoc.options.encoding = 'UTF-8'
+
+dependencies {
+  compile 'com.google.api:gax:{{version.gax}}'
+  testCompile 'com.google.api:gax:{{version.gax}}:testlib'
+  compile 'com.google.api:gax-httpjson:{{version.gax_httpjson}}'
+  testCompile 'com.google.api:gax-httpjson:{{version.gax_httpjson}}:testlib'
+  testCompile '{{maven.junit_junit}}'
+  {{extra_deps}}
+}
+
+task smokeTest(type: Test) {
+  filter {
+    includeTestsMatching "*SmokeTest"
+    setFailOnNoMatchingTests false
+  }
+}
+
+test {
+  exclude "**/*SmokeTest*"
+}
+
+sourceSets {
+  main {
+    java {
+      srcDir 'src/main/java'
+    }
+  }
+}
+
+clean {
+  delete 'all-jars'
+}
+
+task allJars(type: Copy) {
+  dependsOn test, jar
+  into 'all-jars'
+  // Replace with `from configurations.testRuntime, jar` to include test dependencies
+  from configurations.runtime, jar
+}
diff --git a/rules_java_gapic/resources/gradle/grpc.gradle.tmpl b/rules_java_gapic/resources/gradle/grpc.gradle.tmpl
index d5dfa3f3de..fbae0add76 100644
--- a/rules_java_gapic/resources/gradle/grpc.gradle.tmpl
+++ b/rules_java_gapic/resources/gradle/grpc.gradle.tmpl
@@ -9,8 +9,8 @@ apply plugin: 'java'
 description = 'GRPC library for {{name}}'
 group = 'com.google.api.grpc'
 version = (findProperty('version') == 'unspecified') ? '0.0.0-SNAPSHOT' : version
-sourceCompatibility = 1.7
-targetCompatibility = 1.7
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
 
 repositories {
   mavenCentral()
diff --git a/rules_java_gapic/resources/gradle/proto.gradle.tmpl b/rules_java_gapic/resources/gradle/proto.gradle.tmpl
index ad5e20fc33..27f0bf8448 100644
--- a/rules_java_gapic/resources/gradle/proto.gradle.tmpl
+++ b/rules_java_gapic/resources/gradle/proto.gradle.tmpl
@@ -9,8 +9,8 @@ apply plugin: 'java'
 description = 'PROTO library for {{name}}'
 group = 'com.google.api.grpc'
 version = (findProperty('version') == 'unspecified') ? '0.0.0-SNAPSHOT' : version
-sourceCompatibility = 1.7
-targetCompatibility = 1.7
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
 
 repositories {
   mavenCentral()
diff --git a/src/main/java/com/google/api/generator/Main.java b/src/main/java/com/google/api/generator/Main.java
index 0e1e985e2f..2ad75c19ba 100644
--- a/src/main/java/com/google/api/generator/Main.java
+++ b/src/main/java/com/google/api/generator/Main.java
@@ -14,34 +14,18 @@
 
 package com.google.api.generator;
 
-import com.google.api.AnnotationsProto;
-import com.google.api.ClientProto;
-import com.google.api.FieldBehaviorProto;
-import com.google.api.ResourceProto;
 import com.google.api.generator.gapic.Generator;
-import com.google.longrunning.OperationsProto;
-import com.google.protobuf.Descriptors.DescriptorValidationException;
 import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest;
 import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse;
 import java.io.IOException;
 
 public class Main {
-  public static void main(String[] args)
-      throws IOException, InterruptedException, DescriptorValidationException {
+  public static void main(String[] args) throws IOException {
     ExtensionRegistry registry = ExtensionRegistry.newInstance();
-    registerAllExtensions(registry);
+    ProtoRegistry.registerAllExtensions(registry);
     CodeGeneratorRequest request = CodeGeneratorRequest.parseFrom(System.in, registry);
     CodeGeneratorResponse response = Generator.generateGapic(request);
     response.writeTo(System.out);
   }
-
-  /** Register all extensions needed to process API protofiles. */
-  private static void registerAllExtensions(ExtensionRegistry extensionRegistry) {
-    OperationsProto.registerAllExtensions(extensionRegistry);
-    AnnotationsProto.registerAllExtensions(extensionRegistry);
-    ClientProto.registerAllExtensions(extensionRegistry);
-    ResourceProto.registerAllExtensions(extensionRegistry);
-    FieldBehaviorProto.registerAllExtensions(extensionRegistry);
-  }
 }
diff --git a/src/main/java/com/google/api/generator/ProtoRegistry.java b/src/main/java/com/google/api/generator/ProtoRegistry.java
new file mode 100644
index 0000000000..da4806bba0
--- /dev/null
+++ b/src/main/java/com/google/api/generator/ProtoRegistry.java
@@ -0,0 +1,33 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator;
+
+import com.google.api.AnnotationsProto;
+import com.google.api.ClientProto;
+import com.google.api.FieldBehaviorProto;
+import com.google.api.ResourceProto;
+import com.google.longrunning.OperationsProto;
+import com.google.protobuf.ExtensionRegistry;
+
+public class ProtoRegistry {
+  /** Register all extensions needed to process API protofiles. */
+  public static void registerAllExtensions(ExtensionRegistry extensionRegistry) {
+    OperationsProto.registerAllExtensions(extensionRegistry);
+    AnnotationsProto.registerAllExtensions(extensionRegistry);
+    ClientProto.registerAllExtensions(extensionRegistry);
+    ResourceProto.registerAllExtensions(extensionRegistry);
+    FieldBehaviorProto.registerAllExtensions(extensionRegistry);
+  }
+}
diff --git a/src/main/java/com/google/api/generator/debug/BUILD.bazel b/src/main/java/com/google/api/generator/debug/BUILD.bazel
new file mode 100644
index 0000000000..048f426a23
--- /dev/null
+++ b/src/main/java/com/google/api/generator/debug/BUILD.bazel
@@ -0,0 +1,27 @@
+load("@rules_java//java:defs.bzl", "java_library")
+
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "debug_files",
+    srcs = glob(["*.java"]),
+)
+
+java_library(
+    name = "debug",
+    srcs = [
+        ":debug_files",
+    ],
+    deps = [
+        "//src/main/java/com/google/api/generator",
+        "//src/main/java/com/google/api/generator/engine",
+        "//src/main/java/com/google/api/generator/engine/ast",
+        "//src/main/java/com/google/api/generator/gapic",
+        "//src/main/java/com/google/api/generator/gapic/model",
+        "//src/main/java/com/google/api/generator/util",
+        "@com_google_googleapis//google/api:api_java_proto",
+        "@com_google_googleapis//google/longrunning:longrunning_java_proto",
+        "@com_google_guava_guava//jar",
+        "@com_google_protobuf//:protobuf_java",
+    ],
+)
diff --git a/src/main/java/com/google/api/generator/debug/CodeGeneratorRequestDumper.java b/src/main/java/com/google/api/generator/debug/CodeGeneratorRequestDumper.java
new file mode 100644
index 0000000000..ef75a6a652
--- /dev/null
+++ b/src/main/java/com/google/api/generator/debug/CodeGeneratorRequestDumper.java
@@ -0,0 +1,42 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.debug;
+
+import com.google.api.generator.ProtoRegistry;
+import com.google.protobuf.ExtensionRegistry;
+import com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest;
+import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse;
+import java.io.IOException;
+
+// Request dumper class, which dumps the CodeGeneratorRequest to a file on disk which will be
+// identical to the one passed to the Main class during normal execution. The dumped file then can
+// be used to run this gapic-generator directly (instead of relying on protoc to start the process),
+// which would give much greater flexibility in terms of debugging features, like attaching a
+// debugger, easier work with stdout and stderr etc.
+public class CodeGeneratorRequestDumper {
+  public static void main(String[] args) throws IOException {
+    ExtensionRegistry registry = ExtensionRegistry.newInstance();
+    ProtoRegistry.registerAllExtensions(registry);
+    CodeGeneratorRequest request = CodeGeneratorRequest.parseFrom(System.in, registry);
+
+    CodeGeneratorResponse.Builder response = CodeGeneratorResponse.newBuilder();
+    response
+        .setSupportedFeatures(CodeGeneratorResponse.Feature.FEATURE_PROTO3_OPTIONAL_VALUE)
+        .addFileBuilder()
+        .setName("desc-dump.bin")
+        .setContentBytes(request.toByteString());
+    response.build().writeTo(System.out);
+  }
+}
diff --git a/src/main/java/com/google/api/generator/debug/CodeGeneratorRequestFileToGapicMain.java b/src/main/java/com/google/api/generator/debug/CodeGeneratorRequestFileToGapicMain.java
new file mode 100644
index 0000000000..5cbbb05608
--- /dev/null
+++ b/src/main/java/com/google/api/generator/debug/CodeGeneratorRequestFileToGapicMain.java
@@ -0,0 +1,45 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.debug;
+
+import com.google.api.generator.ProtoRegistry;
+import com.google.api.generator.gapic.Generator;
+import com.google.protobuf.ExtensionRegistry;
+import com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest;
+import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+// A generator entry point class, similar to Main but reads the CodeGeneratorRequest directly from a
+// file instead of relying on protoc to pipe it in.
+public class CodeGeneratorRequestFileToGapicMain {
+  public static void main(String[] args) throws IOException {
+    ExtensionRegistry registry = ExtensionRegistry.newInstance();
+    ProtoRegistry.registerAllExtensions(registry);
+
+    String inputFile = args[0];
+    String outputFile = args[1];
+
+    try (InputStream inputStream = new FileInputStream(inputFile);
+        OutputStream outputStream = new FileOutputStream(outputFile)) {
+      CodeGeneratorRequest request = CodeGeneratorRequest.parseFrom(inputStream, registry);
+      CodeGeneratorResponse response = Generator.generateGapic(request);
+      response.writeTo(outputStream);
+    }
+  }
+}
diff --git a/src/main/java/com/google/api/generator/engine/ast/AnnotationNode.java b/src/main/java/com/google/api/generator/engine/ast/AnnotationNode.java
index a7c69d8729..1a3412aa6c 100644
--- a/src/main/java/com/google/api/generator/engine/ast/AnnotationNode.java
+++ b/src/main/java/com/google/api/generator/engine/ast/AnnotationNode.java
@@ -25,7 +25,7 @@ public abstract class AnnotationNode implements AstNode {
   public static AnnotationNode DEPRECATED =
       AnnotationNode.builder().setType(annotationType(Deprecated.class)).build();
 
-  private static TypeNode annotationType(Class clazz) {
+  private static TypeNode annotationType(Class<?> clazz) {
     return TypeNode.withReference(ConcreteReference.withClazz(clazz));
   }
 
@@ -41,11 +41,12 @@ public void accept(AstNodeVisitor visitor) {
     visitor.visit(this);
   }
 
+  public static AnnotationNode withTypeAndDescription(TypeNode type, String description) {
+    return AnnotationNode.builder().setType(type).setDescription(description).build();
+  }
+
   public static AnnotationNode withSuppressWarnings(String description) {
-    return AnnotationNode.builder()
-        .setType(annotationType(SuppressWarnings.class))
-        .setDescription(description)
-        .build();
+    return withTypeAndDescription(annotationType(SuppressWarnings.class), description);
   }
 
   public static AnnotationNode withType(TypeNode type) {
diff --git a/src/main/java/com/google/api/generator/engine/ast/ArithmeticOperationExpr.java b/src/main/java/com/google/api/generator/engine/ast/ArithmeticOperationExpr.java
index 1a362758fd..886ec56ad4 100644
--- a/src/main/java/com/google/api/generator/engine/ast/ArithmeticOperationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/ArithmeticOperationExpr.java
@@ -24,8 +24,10 @@ public abstract class ArithmeticOperationExpr implements OperationExpr {
 
   public abstract Expr rhsExpr();
 
+  @Override
   public abstract OperatorKind operatorKind();
 
+  @Override
   public abstract TypeNode type();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/AssignmentExpr.java b/src/main/java/com/google/api/generator/engine/ast/AssignmentExpr.java
index 9223e41783..1314505d1f 100644
--- a/src/main/java/com/google/api/generator/engine/ast/AssignmentExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/AssignmentExpr.java
@@ -64,8 +64,10 @@ public AssignmentExpr build() {
         if (rhsType != TypeNode.NULL && !lhsType.isSupertypeOrEquals(rhsType)) {
           throw new TypeMismatchException(
               String.format(
-                  "LHS type %s must be a supertype of the RHS type %s",
-                  lhsType.reference().name(), rhsType.reference().name()));
+                  "LHS type %s of variable %s must be a supertype of the RHS type %s",
+                  lhsType.reference().name(),
+                  assignmentExpr.variableExpr().variable().identifier(),
+                  rhsType.reference().name()));
         }
       }
 
diff --git a/src/main/java/com/google/api/generator/engine/ast/AssignmentOperationExpr.java b/src/main/java/com/google/api/generator/engine/ast/AssignmentOperationExpr.java
index af73f0b44f..4c2cfeec2e 100644
--- a/src/main/java/com/google/api/generator/engine/ast/AssignmentOperationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/AssignmentOperationExpr.java
@@ -23,6 +23,7 @@ public abstract class AssignmentOperationExpr implements OperationExpr {
 
   public abstract Expr valueExpr();
 
+  @Override
   public abstract OperatorKind operatorKind();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/BlockComment.java b/src/main/java/com/google/api/generator/engine/ast/BlockComment.java
index 00f98aa2ec..9a9bc0d0cc 100644
--- a/src/main/java/com/google/api/generator/engine/ast/BlockComment.java
+++ b/src/main/java/com/google/api/generator/engine/ast/BlockComment.java
@@ -18,6 +18,7 @@
 
 @AutoValue
 public abstract class BlockComment implements Comment {
+  @Override
   public abstract String comment();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/ConcreteReference.java b/src/main/java/com/google/api/generator/engine/ast/ConcreteReference.java
index 144c4beca1..5af0dbe869 100644
--- a/src/main/java/com/google/api/generator/engine/ast/ConcreteReference.java
+++ b/src/main/java/com/google/api/generator/engine/ast/ConcreteReference.java
@@ -32,10 +32,10 @@ public abstract class ConcreteReference implements Reference {
   private static final String RIGHT_ANGLE = ">";
   private static final String QUESTION_MARK = "?";
 
-  private static final Class WILDCARD_CLAZZ = ReferenceWildcard.class;
+  private static final Class<?> WILDCARD_CLAZZ = ReferenceWildcard.class;
 
   // Private.
-  abstract Class clazz();
+  abstract Class<?> clazz();
 
   @Override
   public void accept(AstNodeVisitor visitor) {
@@ -105,7 +105,7 @@ public ImmutableList<String> enclosingClassNames() {
     }
     // The innermost type will be the last element in the list.
     ImmutableList.Builder<String> listBuilder = new ImmutableList.Builder<>();
-    Class currentClz = clazz();
+    Class<?> currentClz = clazz();
     while (currentClz.getEnclosingClass() != null) {
       listBuilder.add(currentClz.getEnclosingClass().getSimpleName());
       currentClz = currentClz.getEnclosingClass();
@@ -198,7 +198,7 @@ public Reference copyAndSetGenerics(List<Reference> generics) {
     return toBuilder().setGenerics(generics).build();
   }
 
-  public static ConcreteReference withClazz(Class clazz) {
+  public static ConcreteReference withClazz(Class<?> clazz) {
     return builder().setClazz(clazz).build();
   }
 
@@ -222,7 +222,7 @@ public static Builder builder() {
 
   @AutoValue.Builder
   public abstract static class Builder {
-    public abstract Builder setClazz(Class clazz);
+    public abstract Builder setClazz(Class<?> clazz);
 
     public abstract Builder setUseFullName(boolean useFullName);
 
@@ -239,7 +239,7 @@ public Builder setGenerics(Reference... references) {
     public abstract ConcreteReference autoBuild();
 
     // Private.
-    abstract Class clazz();
+    abstract Class<?> clazz();
 
     abstract ImmutableList<Reference> generics();
 
diff --git a/src/main/java/com/google/api/generator/engine/ast/EnumRefExpr.java b/src/main/java/com/google/api/generator/engine/ast/EnumRefExpr.java
index 9c2c49e756..8dcf18679b 100644
--- a/src/main/java/com/google/api/generator/engine/ast/EnumRefExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/EnumRefExpr.java
@@ -21,6 +21,7 @@
 public abstract class EnumRefExpr implements Expr {
   public abstract IdentifierNode identifier();
 
+  @Override
   public abstract TypeNode type();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/Expr.java b/src/main/java/com/google/api/generator/engine/ast/Expr.java
index 6adc7a4fa5..134d2464d8 100644
--- a/src/main/java/com/google/api/generator/engine/ast/Expr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/Expr.java
@@ -17,5 +17,6 @@
 public interface Expr extends AstNode {
   TypeNode type();
 
+  @Override
   void accept(AstNodeVisitor visitor);
 }
diff --git a/src/main/java/com/google/api/generator/engine/ast/LogicalOperationExpr.java b/src/main/java/com/google/api/generator/engine/ast/LogicalOperationExpr.java
index 2387345d31..9210ec3593 100644
--- a/src/main/java/com/google/api/generator/engine/ast/LogicalOperationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/LogicalOperationExpr.java
@@ -24,6 +24,7 @@ public abstract class LogicalOperationExpr implements OperationExpr {
 
   public abstract Expr rhsExpr();
 
+  @Override
   public abstract OperatorKind operatorKind();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/MethodDefinition.java b/src/main/java/com/google/api/generator/engine/ast/MethodDefinition.java
index 3067dfc49a..4b65d14789 100644
--- a/src/main/java/com/google/api/generator/engine/ast/MethodDefinition.java
+++ b/src/main/java/com/google/api/generator/engine/ast/MethodDefinition.java
@@ -244,20 +244,18 @@ public MethodDefinition build() {
             "Abstract methods cannot be static, final, or private");
       }
 
-      // If this method overrides another, ensure that the Override annotaiton is the last one.
+      // If this method overrides another, ensure that the Override annotation is the last one.
       ImmutableList<AnnotationNode> processedAnnotations = annotations();
       if (isOverride()) {
         processedAnnotations =
-            annotations()
-                .<AnnotationNode>builder()
+            ImmutableList.<AnnotationNode>builder()
                 .addAll(annotations())
                 .add(AnnotationNode.OVERRIDE)
                 .build();
       }
       // Remove duplicates while maintaining insertion order.
       setAnnotations(
-          new LinkedHashSet<AnnotationNode>(processedAnnotations)
-              .stream().collect(Collectors.toList()));
+          new LinkedHashSet<>(processedAnnotations).stream().collect(Collectors.toList()));
 
       MethodDefinition method = autoBuild();
 
diff --git a/src/main/java/com/google/api/generator/engine/ast/MethodInvocationExpr.java b/src/main/java/com/google/api/generator/engine/ast/MethodInvocationExpr.java
index c7970e2990..2a0c2a45c4 100644
--- a/src/main/java/com/google/api/generator/engine/ast/MethodInvocationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/MethodInvocationExpr.java
@@ -126,6 +126,9 @@ public MethodInvocationExpr build() {
           "generics",
           String.format("method invocation of %s", methodInvocationExpr.methodIdentifier().name()));
 
+      // TODO(v2): If type-checking is ever added for arguments, beware of lambdas and their type
+      // workarounds.
+
       return methodInvocationExpr;
     }
   }
diff --git a/src/main/java/com/google/api/generator/engine/ast/NewObjectExpr.java b/src/main/java/com/google/api/generator/engine/ast/NewObjectExpr.java
index 50fbbed983..bbba011dff 100644
--- a/src/main/java/com/google/api/generator/engine/ast/NewObjectExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/NewObjectExpr.java
@@ -23,6 +23,7 @@
 
 @AutoValue
 public abstract class NewObjectExpr implements Expr {
+  @Override
   public abstract TypeNode type();
 
   public abstract ImmutableList<Expr> arguments();
diff --git a/src/main/java/com/google/api/generator/engine/ast/ObjectValue.java b/src/main/java/com/google/api/generator/engine/ast/ObjectValue.java
index 49dd6abd9e..3cde72c4e9 100644
--- a/src/main/java/com/google/api/generator/engine/ast/ObjectValue.java
+++ b/src/main/java/com/google/api/generator/engine/ast/ObjectValue.java
@@ -15,7 +15,9 @@
 package com.google.api.generator.engine.ast;
 
 public interface ObjectValue extends Value {
+  @Override
   TypeNode type();
 
+  @Override
   String value();
 }
diff --git a/src/main/java/com/google/api/generator/engine/ast/OperationExpr.java b/src/main/java/com/google/api/generator/engine/ast/OperationExpr.java
index 924a6a6930..36473e6e97 100644
--- a/src/main/java/com/google/api/generator/engine/ast/OperationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/OperationExpr.java
@@ -18,7 +18,9 @@ public interface OperationExpr extends Expr {
 
   OperatorKind operatorKind();
 
+  @Override
   TypeNode type();
 
+  @Override
   void accept(AstNodeVisitor visitor);
 }
diff --git a/src/main/java/com/google/api/generator/engine/ast/Reference.java b/src/main/java/com/google/api/generator/engine/ast/Reference.java
index fdc2c5c5ee..4dce11783f 100644
--- a/src/main/java/com/google/api/generator/engine/ast/Reference.java
+++ b/src/main/java/com/google/api/generator/engine/ast/Reference.java
@@ -19,6 +19,7 @@
 import javax.annotation.Nullable;
 
 public interface Reference extends AstNode {
+  @Override
   void accept(AstNodeVisitor visitor);
 
   ImmutableList<Reference> generics();
diff --git a/src/main/java/com/google/api/generator/engine/ast/ReferenceConstructorExpr.java b/src/main/java/com/google/api/generator/engine/ast/ReferenceConstructorExpr.java
index 25940b0d3d..b68ff61ded 100644
--- a/src/main/java/com/google/api/generator/engine/ast/ReferenceConstructorExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/ReferenceConstructorExpr.java
@@ -28,6 +28,7 @@ public enum KeywordKind {
     SUPER
   }
 
+  @Override
   public abstract TypeNode type();
 
   public abstract KeywordKind keywordKind();
@@ -73,7 +74,7 @@ public Builder setArguments(Expr... arguments) {
     public ReferenceConstructorExpr build() {
       ReferenceConstructorExpr referenceConstructorExpr = autoBuild();
       Preconditions.checkState(
-          referenceConstructorExpr.type().isReferenceType(referenceConstructorExpr.type()),
+          TypeNode.isReferenceType(referenceConstructorExpr.type()),
           "A this/super constructor must have a reference type.");
 
       NodeValidator.checkNoNullElements(
diff --git a/src/main/java/com/google/api/generator/engine/ast/RelationalOperationExpr.java b/src/main/java/com/google/api/generator/engine/ast/RelationalOperationExpr.java
index 80f0e4711b..d143abad5e 100644
--- a/src/main/java/com/google/api/generator/engine/ast/RelationalOperationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/RelationalOperationExpr.java
@@ -23,6 +23,7 @@ public abstract class RelationalOperationExpr implements OperationExpr {
 
   public abstract Expr rhsExpr();
 
+  @Override
   public abstract OperatorKind operatorKind();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/Statement.java b/src/main/java/com/google/api/generator/engine/ast/Statement.java
index 041d5bfd0f..954b279fd7 100644
--- a/src/main/java/com/google/api/generator/engine/ast/Statement.java
+++ b/src/main/java/com/google/api/generator/engine/ast/Statement.java
@@ -15,5 +15,6 @@
 package com.google.api.generator.engine.ast;
 
 public interface Statement extends AstNode {
+  @Override
   void accept(AstNodeVisitor visitor);
 }
diff --git a/src/main/java/com/google/api/generator/engine/ast/StringObjectValue.java b/src/main/java/com/google/api/generator/engine/ast/StringObjectValue.java
index c121df71c3..602c0dbf82 100644
--- a/src/main/java/com/google/api/generator/engine/ast/StringObjectValue.java
+++ b/src/main/java/com/google/api/generator/engine/ast/StringObjectValue.java
@@ -20,6 +20,7 @@
 
 @AutoValue
 public abstract class StringObjectValue implements ObjectValue {
+  @Override
   public abstract String value();
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/ast/ThrowExpr.java b/src/main/java/com/google/api/generator/engine/ast/ThrowExpr.java
index 805499b074..5e4808d28a 100644
--- a/src/main/java/com/google/api/generator/engine/ast/ThrowExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/ThrowExpr.java
@@ -22,12 +22,18 @@
 public abstract class ThrowExpr implements Expr {
   // TODO(miraleung): Refactor with StringObjectValue and possibly with NewObjectExpr.
 
+  @Nullable
+  public abstract Expr throwExpr();
+
   @Override
   public abstract TypeNode type();
 
   @Nullable
   public abstract Expr messageExpr();
 
+  @Nullable
+  public abstract Expr causeExpr();
+
   @Override
   public void accept(AstNodeVisitor visitor) {
     visitor.visit(this);
@@ -39,6 +45,9 @@ public static Builder builder() {
 
   @AutoValue.Builder
   public abstract static class Builder {
+    public abstract Builder setThrowExpr(Expr throwExpr);
+
+    // No-op if setThrowExpr is called.
     public abstract Builder setType(TypeNode type);
 
     public Builder setMessageExpr(String message) {
@@ -47,22 +56,56 @@ public Builder setMessageExpr(String message) {
 
     public abstract Builder setMessageExpr(Expr expr);
 
+    public abstract Builder setCauseExpr(Expr expr);
+
     // Private.
+    abstract Expr throwExpr();
+
     abstract TypeNode type();
 
     abstract Expr messageExpr();
 
+    abstract Expr causeExpr();
+
     abstract ThrowExpr autoBuild();
 
     public ThrowExpr build() {
+      if (throwExpr() != null) {
+        setType(throwExpr().type());
+        Preconditions.checkState(
+            messageExpr() == null && causeExpr() == null,
+            "Only one of throwExpr or [messageExpr or causeExpr, inclusive] can be present.");
+
+        if (throwExpr() instanceof VariableExpr) {
+          Preconditions.checkState(
+              !((VariableExpr) throwExpr()).isDecl(), "Cannot throw a variable declaration");
+        }
+
+        Preconditions.checkState(
+            TypeNode.isExceptionType(throwExpr().type()),
+            String.format("Only exception types can be thrown, found %s", throwExpr().type()));
+
+        return autoBuild();
+      }
+
       Preconditions.checkState(
           TypeNode.isExceptionType(type()),
           String.format("Type %s must be an exception type", type()));
+
       if (messageExpr() != null) {
         Preconditions.checkState(
             messageExpr().type().equals(TypeNode.STRING),
             String.format("Message expression type must be a string for exception %s", type()));
       }
+
+      if (causeExpr() != null) {
+        Preconditions.checkState(
+            TypeNode.THROWABLE.reference().isSupertypeOrEquals(causeExpr().type().reference()),
+            String.format(
+                "Cause expression type must be a subclass of Throwable, but found %s",
+                causeExpr().type()));
+      }
+
       return autoBuild();
     }
   }
diff --git a/src/main/java/com/google/api/generator/engine/ast/TryCatchStatement.java b/src/main/java/com/google/api/generator/engine/ast/TryCatchStatement.java
index 3634374259..1280635e38 100644
--- a/src/main/java/com/google/api/generator/engine/ast/TryCatchStatement.java
+++ b/src/main/java/com/google/api/generator/engine/ast/TryCatchStatement.java
@@ -17,8 +17,10 @@
 import com.google.auto.value.AutoValue;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 @AutoValue
@@ -26,11 +28,12 @@ public abstract class TryCatchStatement implements Statement {
 
   // Required.
   public abstract ImmutableList<Statement> tryBody();
+
   // Optional only if the sample code bit is set (i.e. this is sample code).
-  @Nullable
-  public abstract VariableExpr catchVariableExpr();
+  public abstract List<VariableExpr> catchVariableExprs();
   // Optional only if the sample code bit is set (i.e. this is sample code).
-  public abstract ImmutableList<Statement> catchBody();
+  public abstract List<List<Statement>> catchBlocks();
+
   // Optional.
   @Nullable
   public abstract AssignmentExpr tryResourceExpr();
@@ -44,8 +47,9 @@ public void accept(AstNodeVisitor visitor) {
 
   public static Builder builder() {
     return new AutoValue_TryCatchStatement.Builder()
-        .setIsSampleCode(false)
-        .setCatchBody(Collections.emptyList());
+        .setCatchVariableExprs(Collections.emptyList())
+        .setCatchBlocks(Collections.emptyList())
+        .setIsSampleCode(false);
   }
 
   @AutoValue.Builder
@@ -54,32 +58,61 @@ public abstract static class Builder {
 
     public abstract Builder setTryBody(List<Statement> body);
 
-    public abstract Builder setCatchVariableExpr(VariableExpr variableExpr);
+    public abstract Builder setIsSampleCode(boolean isSampleCode);
 
-    public abstract Builder setCatchBody(List<Statement> body);
+    public Builder addCatch(@Nonnull VariableExpr variableExpr, List<Statement> body) {
+      List<VariableExpr> catchVarExprs = new ArrayList<>(catchVariableExprs());
+      catchVarExprs.add(variableExpr);
+      setCatchVariableExprs(catchVarExprs);
 
-    public abstract Builder setIsSampleCode(boolean isSampleCode);
+      List<List<Statement>> blocks = new ArrayList<>(catchBlocks());
+      blocks.add(body);
+      return setCatchBlocks(blocks);
+    }
+
+    // Private.
+    abstract Builder setCatchVariableExprs(List<VariableExpr> variableExpr);
+
+    abstract Builder setCatchBlocks(List<List<Statement>> body);
+
+    abstract ImmutableList<Statement> tryBody();
+
+    abstract boolean isSampleCode();
+
+    abstract List<VariableExpr> catchVariableExprs();
+
+    abstract List<List<Statement>> catchBlocks();
 
     abstract TryCatchStatement autoBuild();
 
     public TryCatchStatement build() {
-      TryCatchStatement tryCatchStatement = autoBuild();
-      NodeValidator.checkNoNullElements(tryCatchStatement.tryBody(), "try body", "try-catch");
-      NodeValidator.checkNoNullElements(tryCatchStatement.catchBody(), "catch body", "try-catch");
+      NodeValidator.checkNoNullElements(tryBody(), "try body", "try-catch");
+      NodeValidator.checkNoNullElements(
+          catchVariableExprs(), "catch variable expressions", "try-catch");
+      catchBlocks()
+          .forEach(body -> NodeValidator.checkNoNullElements(body, "catch body", "try-catch"));
 
-      if (!tryCatchStatement.isSampleCode()) {
-        Preconditions.checkNotNull(
-            tryCatchStatement.catchVariableExpr(),
+      if (!isSampleCode()) {
+        Preconditions.checkState(
+            !catchVariableExprs().isEmpty(),
             "Catch variable expression must be set for real, non-sample try-catch blocks.");
         Preconditions.checkState(
-            tryCatchStatement.catchVariableExpr().isDecl(),
-            "Catch variable expression must be a declaration");
+            catchVariableExprs().stream().allMatch(v -> v.isDecl()),
+            "Catch variable expressions must all be declarations");
         Preconditions.checkState(
-            TypeNode.isExceptionType(tryCatchStatement.catchVariableExpr().variable().type()),
-            "Catch variable must be an Exception object reference");
+            catchVariableExprs().stream()
+                .allMatch(v -> TypeNode.isExceptionType(v.variable().type())),
+            "Catch variables must be an Exception object references");
       }
 
-      return tryCatchStatement;
+      // Catch any potential future breakage due to changing addCatch above.
+      Preconditions.checkState(
+          catchVariableExprs().size() == catchBlocks().size(),
+          String.format(
+              "%d catch variables found and %d blocks found, but these numbers must be equal",
+              catchVariableExprs().size(), catchBlocks().size()));
+
+      return autoBuild();
     }
   }
 }
diff --git a/src/main/java/com/google/api/generator/engine/ast/TypeNode.java b/src/main/java/com/google/api/generator/engine/ast/TypeNode.java
index 5685efb1f0..50bcc62657 100644
--- a/src/main/java/com/google/api/generator/engine/ast/TypeNode.java
+++ b/src/main/java/com/google/api/generator/engine/ast/TypeNode.java
@@ -81,6 +81,9 @@ public enum TypeKind {
   public static final TypeNode STRING = withReference(ConcreteReference.withClazz(String.class));
   public static final TypeNode VOID_OBJECT = withReference(ConcreteReference.withClazz(Void.class));
 
+  public static final TypeNode THROWABLE =
+      withReference(ConcreteReference.withClazz(Throwable.class));
+
   public static final TypeNode DEPRECATED =
       withReference(ConcreteReference.withClazz(Deprecated.class));
 
@@ -109,7 +112,7 @@ public int compareTo(TypeNode other) {
       return -1;
     }
 
-    if (this.equals(TypeNode.NULL)) {
+    if (equals(TypeNode.NULL)) {
       // Can't self-compare, so we don't need to check whether the other one is TypeNode.NULL.
       return other.isPrimitiveType() ? 1 : -1;
     }
@@ -158,7 +161,7 @@ public static TypeNode withReference(Reference reference) {
     return TypeNode.builder().setTypeKind(TypeKind.OBJECT).setReference(reference).build();
   }
 
-  public static TypeNode withExceptionClazz(Class clazz) {
+  public static TypeNode withExceptionClazz(Class<?> clazz) {
     Preconditions.checkState(Exception.class.isAssignableFrom(clazz));
     return withReference(ConcreteReference.withClazz(clazz));
   }
@@ -197,11 +200,11 @@ public boolean isPrimitiveType() {
   }
 
   public boolean isProtoPrimitiveType() {
-    return isPrimitiveType() || this.equals(TypeNode.STRING) || this.equals(TypeNode.BYTESTRING);
+    return isPrimitiveType() || equals(TypeNode.STRING) || equals(TypeNode.BYTESTRING);
   }
 
   public boolean isSupertypeOrEquals(TypeNode other) {
-    boolean oneTypeIsNull = this.equals(TypeNode.NULL) ^ other.equals(TypeNode.NULL);
+    boolean oneTypeIsNull = equals(TypeNode.NULL) ^ other.equals(TypeNode.NULL);
     return !isPrimitiveType()
         && !other.isPrimitiveType()
         && isArray() == other.isArray()
@@ -253,20 +256,6 @@ boolean isBoxedTypeEquals(TypeNode other) {
     return Objects.equals(other, BOXED_TYPE_MAP.get(this));
   }
 
-  private static TypeNode createPrimitiveType(TypeKind typeKind) {
-    if (!isPrimitiveType(typeKind)) {
-      throw new IllegalArgumentException("Object is not a primitive type.");
-    }
-    return TypeNode.builder().setTypeKind(typeKind).build();
-  }
-
-  private static TypeNode createPrimitiveArrayType(TypeKind typeKind) {
-    if (typeKind.equals(TypeKind.OBJECT)) {
-      throw new IllegalArgumentException("Object is not a primitive type.");
-    }
-    return TypeNode.builder().setTypeKind(typeKind).setIsArray(true).build();
-  }
-
   private static boolean isPrimitiveType(TypeKind typeKind) {
     return !typeKind.equals(TypeKind.OBJECT);
   }
diff --git a/src/main/java/com/google/api/generator/engine/ast/UnaryOperationExpr.java b/src/main/java/com/google/api/generator/engine/ast/UnaryOperationExpr.java
index 74bda2f21d..3a968b92e0 100644
--- a/src/main/java/com/google/api/generator/engine/ast/UnaryOperationExpr.java
+++ b/src/main/java/com/google/api/generator/engine/ast/UnaryOperationExpr.java
@@ -22,10 +22,13 @@ public abstract class UnaryOperationExpr implements OperationExpr {
 
   public abstract Expr expr();
 
+  @Override
   public abstract OperatorKind operatorKind();
 
+  @Override
   public abstract TypeNode type();
 
+  @Override
   public void accept(AstNodeVisitor visitor) {
     visitor.visit(this);
   }
diff --git a/src/main/java/com/google/api/generator/engine/writer/ImportWriterVisitor.java b/src/main/java/com/google/api/generator/engine/writer/ImportWriterVisitor.java
index d54d1f0dfc..85274e34b9 100644
--- a/src/main/java/com/google/api/generator/engine/writer/ImportWriterVisitor.java
+++ b/src/main/java/com/google/api/generator/engine/writer/ImportWriterVisitor.java
@@ -74,7 +74,6 @@
 
 public class ImportWriterVisitor implements AstNodeVisitor {
   private static final String DOT = ".";
-  private static final String NEWLINE = "\n";
   private static final String PKG_JAVA_LANG = "java.lang";
 
   private final Set<String> staticImports = new TreeSet<>();
@@ -94,7 +93,7 @@ public void clear() {
 
   public void initialize(@Nonnull String currentPackage) {
     this.currentPackage = currentPackage;
-    this.currentClassName = null;
+    currentClassName = null;
   }
 
   public void initialize(@Nonnull String currentPackage, @Nonnull String currentClassName) {
@@ -231,9 +230,19 @@ public void visit(AnonymousClassExpr anonymousClassExpr) {
   @Override
   public void visit(ThrowExpr throwExpr) {
     throwExpr.type().accept(this);
+    // If throwExpr is present, then messageExpr and causeExpr will not be present. Relies on AST
+    // build-time checks.
+    if (throwExpr.throwExpr() != null) {
+      throwExpr.throwExpr().accept(this);
+      return;
+    }
+
     if (throwExpr.messageExpr() != null) {
       throwExpr.messageExpr().accept(this);
     }
+    if (throwExpr.causeExpr() != null) {
+      throwExpr.causeExpr().accept(this);
+    }
   }
 
   @Override
@@ -352,11 +361,13 @@ public void visit(TryCatchStatement tryCatchStatement) {
     statements(tryCatchStatement.tryBody());
 
     Preconditions.checkState(
-        !tryCatchStatement.isSampleCode() && tryCatchStatement.catchVariableExpr() != null,
+        !tryCatchStatement.isSampleCode() && !tryCatchStatement.catchVariableExprs().isEmpty(),
         "Import generation should not be invoked on sample code, but was found when visiting a"
             + " try-catch block");
-    tryCatchStatement.catchVariableExpr().accept(this);
-    statements(tryCatchStatement.catchBody());
+    for (int i = 0; i < tryCatchStatement.catchVariableExprs().size(); i++) {
+      tryCatchStatement.catchVariableExprs().get(i).accept(this);
+      statements(tryCatchStatement.catchBlocks().get(i));
+    }
   }
 
   @Override
diff --git a/src/main/java/com/google/api/generator/engine/writer/JavaWriterVisitor.java b/src/main/java/com/google/api/generator/engine/writer/JavaWriterVisitor.java
index 6b4cbc69d1..b1d750157e 100644
--- a/src/main/java/com/google/api/generator/engine/writer/JavaWriterVisitor.java
+++ b/src/main/java/com/google/api/generator/engine/writer/JavaWriterVisitor.java
@@ -81,7 +81,6 @@ public class JavaWriterVisitor implements AstNodeVisitor {
   private static final String BLOCK_COMMENT_START = "/*";
   private static final String BLOCK_COMMENT_END = "*/";
   private static final String DOT = ".";
-  private static final String ESCAPED_QUOTE = "\"";
   private static final String EQUALS = "=";
   private static final String LEFT_ANGLE = "<";
   private static final String LEFT_BRACE = "{";
@@ -392,6 +391,13 @@ public void visit(AnonymousClassExpr anonymousClassExpr) {
   public void visit(ThrowExpr throwExpr) {
     buffer.append(THROW);
     space();
+    // If throwExpr is present, then messageExpr and causeExpr will not be present. Relies on AST
+    // build-time checks.
+    if (throwExpr.throwExpr() != null) {
+      throwExpr.throwExpr().accept(this);
+      return;
+    }
+
     buffer.append(NEW);
     space();
     throwExpr.type().accept(this);
@@ -399,6 +405,13 @@ public void visit(ThrowExpr throwExpr) {
     if (throwExpr.messageExpr() != null) {
       throwExpr.messageExpr().accept(this);
     }
+    if (throwExpr.causeExpr() != null) {
+      if (throwExpr.messageExpr() != null) {
+        buffer.append(COMMA);
+        space();
+      }
+      throwExpr.causeExpr().accept(this);
+    }
     rightParen();
   }
 
@@ -689,17 +702,17 @@ public void visit(TryCatchStatement tryCatchStatement) {
     statements(tryCatchStatement.tryBody());
     rightBrace();
 
-    if (tryCatchStatement.catchVariableExpr() != null) {
+    for (int i = 0; i < tryCatchStatement.catchVariableExprs().size(); i++) {
       space();
       buffer.append(CATCH);
       space();
       leftParen();
-      tryCatchStatement.catchVariableExpr().accept(this);
+      tryCatchStatement.catchVariableExprs().get(i).accept(this);
       rightParen();
       space();
       leftBrace();
       newline();
-      statements(tryCatchStatement.catchBody());
+      statements(tryCatchStatement.catchBlocks().get(i));
       rightBrace();
     }
     newline();
@@ -737,6 +750,7 @@ public void visit(BreakStatement breakStatement) {
   }
 
   /** =============================== COMMENT =============================== */
+  @Override
   public void visit(LineComment lineComment) {
     // Split comments by new line and add `//` to each line.
     String formattedSource =
@@ -745,6 +759,7 @@ public void visit(LineComment lineComment) {
     buffer.append(formattedSource);
   }
 
+  @Override
   public void visit(BlockComment blockComment) {
     // Split comments by new line and embrace the comment block with `/* */`.
     StringBuilder sourceComment = new StringBuilder();
@@ -758,6 +773,7 @@ public void visit(BlockComment blockComment) {
     buffer.append(JavaFormatter.format(sourceComment.toString()));
   }
 
+  @Override
   public void visit(JavaDocComment javaDocComment) {
     StringBuilder sourceComment = new StringBuilder();
     sourceComment.append(JAVADOC_COMMENT_START).append(NEWLINE);
@@ -851,7 +867,6 @@ public void visit(MethodDefinition methodDefinition) {
       buffer.append(THROWS);
       space();
 
-      int numExceptionsThrown = methodDefinition.throwsExceptions().size();
       Iterator<TypeNode> exceptionIter = methodDefinition.throwsExceptions().iterator();
       while (exceptionIter.hasNext()) {
         TypeNode exceptionType = exceptionIter.next();
diff --git a/src/main/java/com/google/api/generator/gapic/BUILD.bazel b/src/main/java/com/google/api/generator/gapic/BUILD.bazel
index 37a314ed0b..60cbc46d03 100644
--- a/src/main/java/com/google/api/generator/gapic/BUILD.bazel
+++ b/src/main/java/com/google/api/generator/gapic/BUILD.bazel
@@ -7,8 +7,14 @@ filegroup(
     srcs = glob(["*.java"]) + [
         "//src/main/java/com/google/api/generator/gapic/composer:composer_files",
         "//src/main/java/com/google/api/generator/gapic/composer/comment:comment_files",
+        "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue:defaultvalue_files",
+        "//src/main/java/com/google/api/generator/gapic/composer/grpc:grpc_files",
+        "//src/main/java/com/google/api/generator/gapic/composer/grpcrest:grpcrest_files",
+        "//src/main/java/com/google/api/generator/gapic/composer/resourcename:resourcename_files",
+        "//src/main/java/com/google/api/generator/gapic/composer/rest:rest_files",
         "//src/main/java/com/google/api/generator/gapic/composer/samplecode:samplecode_files",
         "//src/main/java/com/google/api/generator/gapic/composer/store:store_files",
+        "//src/main/java/com/google/api/generator/gapic/composer/utils:utils_files",
         "//src/main/java/com/google/api/generator/gapic/model:model_files",
         "//src/main/java/com/google/api/generator/gapic/protoparser:protoparser_files",
         "//src/main/java/com/google/api/generator/gapic/protowriter:protowriter_files",
diff --git a/src/main/java/com/google/api/generator/gapic/composer/BUILD.bazel b/src/main/java/com/google/api/generator/gapic/composer/BUILD.bazel
index ae08ecda8b..0f09405d04 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/BUILD.bazel
+++ b/src/main/java/com/google/api/generator/gapic/composer/BUILD.bazel
@@ -21,7 +21,9 @@ java_library(
         "//src/main/java/com/google/api/generator/gapic/composer/common",
         "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue",
         "//src/main/java/com/google/api/generator/gapic/composer/grpc",
+        "//src/main/java/com/google/api/generator/gapic/composer/grpcrest",
         "//src/main/java/com/google/api/generator/gapic/composer/resourcename",
+        "//src/main/java/com/google/api/generator/gapic/composer/rest",
         "//src/main/java/com/google/api/generator/gapic/composer/samplecode",
         "//src/main/java/com/google/api/generator/gapic/composer/store",
         "//src/main/java/com/google/api/generator/gapic/composer/utils",
diff --git a/src/main/java/com/google/api/generator/gapic/composer/Composer.java b/src/main/java/com/google/api/generator/gapic/composer/Composer.java
index 8dd716eb2a..4eefc2845a 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/Composer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/Composer.java
@@ -15,28 +15,28 @@
 package com.google.api.generator.gapic.composer;
 
 import com.google.api.generator.engine.ast.ClassDefinition;
-import com.google.api.generator.engine.ast.ScopeNode;
 import com.google.api.generator.gapic.composer.comment.CommentComposer;
-import com.google.api.generator.gapic.composer.common.ServiceClientClassComposer;
-import com.google.api.generator.gapic.composer.common.ServiceStubClassComposer;
 import com.google.api.generator.gapic.composer.grpc.GrpcServiceCallableFactoryClassComposer;
 import com.google.api.generator.gapic.composer.grpc.GrpcServiceStubClassComposer;
 import com.google.api.generator.gapic.composer.grpc.MockServiceClassComposer;
 import com.google.api.generator.gapic.composer.grpc.MockServiceImplClassComposer;
+import com.google.api.generator.gapic.composer.grpc.ServiceClientClassComposer;
 import com.google.api.generator.gapic.composer.grpc.ServiceClientTestClassComposer;
 import com.google.api.generator.gapic.composer.grpc.ServiceSettingsClassComposer;
+import com.google.api.generator.gapic.composer.grpc.ServiceStubClassComposer;
 import com.google.api.generator.gapic.composer.grpc.ServiceStubSettingsClassComposer;
+import com.google.api.generator.gapic.composer.grpcrest.HttpJsonServiceClientTestClassComposer;
 import com.google.api.generator.gapic.composer.resourcename.ResourceNameHelperClassComposer;
+import com.google.api.generator.gapic.composer.rest.HttpJsonServiceCallableFactoryClassComposer;
+import com.google.api.generator.gapic.composer.rest.HttpJsonServiceStubClassComposer;
 import com.google.api.generator.gapic.model.GapicClass;
-import com.google.api.generator.gapic.model.GapicClass.Kind;
 import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.GapicPackageInfo;
-import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.model.Transport;
 import com.google.common.annotations.VisibleForTesting;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 public class Composer {
@@ -44,11 +44,7 @@ public static List<GapicClass> composeServiceClasses(GapicContext context) {
     List<GapicClass> clazzes = new ArrayList<>();
     clazzes.addAll(generateServiceClasses(context));
     clazzes.addAll(generateMockClasses(context, context.mixinServices()));
-    clazzes.addAll(
-        generateResourceNameHelperClasses(
-            context.helperResourceNames().values().stream()
-                .map(r -> r)
-                .collect(Collectors.toSet())));
+    clazzes.addAll(generateResourceNameHelperClasses(context));
     return addApacheLicense(clazzes);
   }
 
@@ -65,11 +61,11 @@ public static List<GapicClass> generateServiceClasses(GapicContext context) {
     return clazzes;
   }
 
-  public static List<GapicClass> generateResourceNameHelperClasses(
-      Set<ResourceName> resourceNames) {
-    return resourceNames.stream()
+  public static List<GapicClass> generateResourceNameHelperClasses(GapicContext context) {
+    return context.helperResourceNames().values().stream()
+        .distinct()
         .filter(r -> !r.isOnlyWildcard())
-        .map(r -> ResourceNameHelperClassComposer.instance().generate(r))
+        .map(r -> ResourceNameHelperClassComposer.instance().generate(r, context))
         .collect(Collectors.toList());
   }
 
@@ -79,10 +75,42 @@ public static List<GapicClass> generateStubClasses(GapicContext context) {
         .services()
         .forEach(
             s -> {
-              clazzes.add(ServiceStubClassComposer.instance().generate(context, s));
-              clazzes.add(ServiceStubSettingsClassComposer.instance().generate(context, s));
-              clazzes.add(GrpcServiceCallableFactoryClassComposer.instance().generate(context, s));
-              clazzes.add(GrpcServiceStubClassComposer.instance().generate(context, s));
+              if (context.transport() == Transport.REST) {
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.rest.ServiceStubClassComposer.instance()
+                        .generate(context, s));
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.rest.ServiceStubSettingsClassComposer
+                        .instance()
+                        .generate(context, s));
+                clazzes.add(
+                    HttpJsonServiceCallableFactoryClassComposer.instance().generate(context, s));
+                clazzes.add(HttpJsonServiceStubClassComposer.instance().generate(context, s));
+              } else if (context.transport() == Transport.GRPC) {
+                clazzes.add(ServiceStubClassComposer.instance().generate(context, s));
+                clazzes.add(ServiceStubSettingsClassComposer.instance().generate(context, s));
+                clazzes.add(
+                    GrpcServiceCallableFactoryClassComposer.instance().generate(context, s));
+                clazzes.add(GrpcServiceStubClassComposer.instance().generate(context, s));
+              } else if (context.transport() == Transport.GRPC_REST) {
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.grpcrest.ServiceStubClassComposer
+                        .instance()
+                        .generate(context, s));
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.grpcrest
+                        .ServiceStubSettingsClassComposer.instance()
+                        .generate(context, s));
+                clazzes.add(
+                    GrpcServiceCallableFactoryClassComposer.instance().generate(context, s));
+                clazzes.add(GrpcServiceStubClassComposer.instance().generate(context, s));
+                clazzes.add(
+                    HttpJsonServiceCallableFactoryClassComposer.instance().generate(context, s));
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.grpcrest
+                        .HttpJsonServiceStubClassComposer.instance()
+                        .generate(context, s));
+              }
             });
     return clazzes;
   }
@@ -93,8 +121,28 @@ public static List<GapicClass> generateClientSettingsClasses(GapicContext contex
         .services()
         .forEach(
             s -> {
-              clazzes.add(ServiceClientClassComposer.instance().generate(context, s));
-              clazzes.add(ServiceSettingsClassComposer.instance().generate(context, s));
+              if (context.transport() == Transport.REST) {
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.rest.ServiceClientClassComposer
+                        .instance()
+                        .generate(context, s));
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.rest.ServiceSettingsClassComposer
+                        .instance()
+                        .generate(context, s));
+              } else if (context.transport() == Transport.GRPC) {
+                clazzes.add(ServiceClientClassComposer.instance().generate(context, s));
+                clazzes.add(ServiceSettingsClassComposer.instance().generate(context, s));
+              } else if (context.transport() == Transport.GRPC_REST) {
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.grpcrest.ServiceClientClassComposer
+                        .instance()
+                        .generate(context, s));
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.grpcrest.ServiceSettingsClassComposer
+                        .instance()
+                        .generate(context, s));
+              }
             });
     return clazzes;
   }
@@ -103,33 +151,39 @@ public static List<GapicClass> generateMockClasses(GapicContext context, List<Se
     List<GapicClass> clazzes = new ArrayList<>();
     services.forEach(
         s -> {
-          clazzes.add(MockServiceClassComposer.instance().generate(context, s));
-          clazzes.add(MockServiceImplClassComposer.instance().generate(context, s));
+          if (context.transport() == Transport.REST) {
+            // REST transport tests donot not use mock services.
+          } else if (context.transport() == Transport.GRPC) {
+            clazzes.add(MockServiceClassComposer.instance().generate(context, s));
+            clazzes.add(MockServiceImplClassComposer.instance().generate(context, s));
+          } else if (context.transport() == Transport.GRPC_REST) {
+            clazzes.add(MockServiceClassComposer.instance().generate(context, s));
+            clazzes.add(MockServiceImplClassComposer.instance().generate(context, s));
+          }
         });
     return clazzes;
   }
 
   public static List<GapicClass> generateTestClasses(GapicContext context) {
-    return context.services().stream()
-        .map(s -> ServiceClientTestClassComposer.instance().generate(context, s))
-        .collect(Collectors.toList());
-  }
-
-  /** ====================== HELPERS ==================== */
-  // TODO(miraleung): Add method list.
-  private static GapicClass generateGenericClass(Kind kind, String name, Service service) {
-    String pakkage = service.pakkage();
-    if (kind.equals(Kind.STUB)) {
-      pakkage += ".stub";
-    }
+    List<GapicClass> clazzes = new ArrayList<>();
+    context
+        .services()
+        .forEach(
+            s -> {
+              if (context.transport() == Transport.REST) {
+                clazzes.add(
+                    com.google.api.generator.gapic.composer.rest.ServiceClientTestClassComposer
+                        .instance()
+                        .generate(context, s));
+              } else if (context.transport() == Transport.GRPC) {
+                clazzes.add(ServiceClientTestClassComposer.instance().generate(context, s));
+              } else if (context.transport() == Transport.GRPC_REST) {
+                clazzes.add(ServiceClientTestClassComposer.instance().generate(context, s));
+                clazzes.add(HttpJsonServiceClientTestClassComposer.instance().generate(context, s));
+              }
+            });
 
-    ClassDefinition classDef =
-        ClassDefinition.builder()
-            .setPackageString(pakkage)
-            .setName(name)
-            .setScope(ScopeNode.PUBLIC)
-            .build();
-    return GapicClass.create(kind, classDef);
+    return clazzes;
   }
 
   @VisibleForTesting
diff --git a/src/main/java/com/google/api/generator/gapic/composer/comment/ServiceClientCommentComposer.java b/src/main/java/com/google/api/generator/gapic/composer/comment/ServiceClientCommentComposer.java
index 8ffeace7c5..e8f8a05681 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/comment/ServiceClientCommentComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/comment/ServiceClientCommentComposer.java
@@ -33,7 +33,6 @@
 
 public class ServiceClientCommentComposer {
   // Tokens.
-  private static final String COLON = ":";
   private static final String EMPTY_STRING = "";
   private static final String API_EXCEPTION_TYPE_NAME = "com.google.api.gax.rpc.ApiException";
   private static final String EXCEPTION_CONDITION = "if the remote call fails";
diff --git a/src/main/java/com/google/api/generator/gapic/composer/comment/SettingsCommentComposer.java b/src/main/java/com/google/api/generator/gapic/composer/comment/SettingsCommentComposer.java
index 5e10eb9cd5..7f2c83e4a2 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/comment/SettingsCommentComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/comment/SettingsCommentComposer.java
@@ -16,7 +16,6 @@
 
 import com.google.api.generator.engine.ast.CommentStatement;
 import com.google.api.generator.engine.ast.JavaDocComment;
-import com.google.api.generator.engine.ast.LineComment;
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
@@ -28,7 +27,6 @@
 public class SettingsCommentComposer {
   private static final String COLON = ":";
 
-  private static final String STUB_PATTERN = "%sStub";
   private static final String BUILDER_CLASS_DOC_PATTERN = "Builder for %s.";
   private static final String CALL_SETTINGS_METHOD_DOC_PATTERN =
       "Returns the object with the settings used for calls to %s.";
@@ -61,6 +59,8 @@ public class SettingsCommentComposer {
       toSimpleComment("Returns a builder for the default ExecutorProvider for this service.");
   public static final CommentStatement DEFAULT_SERVICE_ENDPOINT_METHOD_COMMENT =
       toSimpleComment("Returns the default service endpoint.");
+  public static final CommentStatement DEFAULT_SERVICE_MTLS_ENDPOINT_METHOD_COMMENT =
+      toSimpleComment("Returns the default mTLS service endpoint.");
   public static final CommentStatement DEFAULT_SERVICE_SCOPES_METHOD_COMMENT =
       toSimpleComment("Returns the default service scopes.");
 
@@ -78,7 +78,6 @@ public class SettingsCommentComposer {
 
   public static final List<CommentStatement> APPLY_TO_ALL_UNARY_METHODS_METHOD_COMMENTS =
       Arrays.asList(
-              LineComment.withComment("NEXT_MAJOR_VER: remove 'throws Exception'."),
               JavaDocComment.builder()
                   .addComment(
                       "Applies the given settings updater function to all of the unary API methods"
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceCallableFactoryClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceCallableFactoryClassComposer.java
index 280c9712b2..09aa5948a0 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceCallableFactoryClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceCallableFactoryClassComposer.java
@@ -44,6 +44,7 @@
 import com.google.api.generator.gapic.model.Service;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 import javax.annotation.Generated;
@@ -102,6 +103,13 @@ protected List<AnnotationNode> createClassAnnotations(Service service, TypeStore
     return annotations;
   }
 
+  /**
+   * Construct the type to be implemented by the generated callable factory.
+   *
+   * @param typeStore type store with common types
+   * @return {@code TypeNode} containing the interface to be implemented by the generated callable
+   *     factory class.
+   */
   protected abstract List<TypeNode> createClassImplements(TypeStore typeStore);
 
   protected List<MethodDefinition> createClassMethods(TypeStore typeStore) {
@@ -185,6 +193,28 @@ protected MethodDefinition createGenericCallableMethod(
       List<Object> transportCallSettingsTemplateObjects,
       String callSettingsVariantName,
       List<Object> callSettingsTemplateObjects) {
+    return createGenericCallableMethod(
+        typeStore,
+        methodTemplateNames,
+        returnCallableKindName,
+        returnCallableTemplateNames,
+        methodVariantName,
+        transportCallSettingsTemplateObjects,
+        callSettingsVariantName,
+        callSettingsTemplateObjects,
+        Collections.emptyList());
+  }
+
+  protected MethodDefinition createGenericCallableMethod(
+      TypeStore typeStore,
+      List<String> methodTemplateNames,
+      String returnCallableKindName,
+      List<String> returnCallableTemplateNames,
+      String methodVariantName,
+      List<Object> transportCallSettingsTemplateObjects,
+      String callSettingsVariantName,
+      List<Object> callSettingsTemplateObjects,
+      List<AnnotationNode> annotations) {
 
     String methodName = String.format("create%sCallable", methodVariantName);
     String callSettingsTypeName = String.format("%sCallSettings", callSettingsVariantName);
@@ -227,7 +257,7 @@ protected MethodDefinition createGenericCallableMethod(
               .setVariable(
                   Variable.builder()
                       .setName("operationsStub")
-                      .setType(getTransportContext().operationsStubType())
+                      .setType(getTransportContext().operationsStubTypes().get(0))
                       .build())
               .setIsDecl(true)
               .build());
@@ -254,11 +284,12 @@ protected MethodDefinition createGenericCallableMethod(
         .setName(methodName)
         .setArguments(arguments)
         .setReturnExpr(returnExpr)
+        .setAnnotations(annotations)
         .build();
   }
 
   private static TypeStore createTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             // Gax-java classes.
             BatchingCallSettings.class,
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/ServiceClientClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientClassComposer.java
similarity index 93%
rename from src/main/java/com/google/api/generator/gapic/composer/common/ServiceClientClassComposer.java
rename to src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientClassComposer.java
index 97cf85f5ad..528d24d202 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/ServiceClientClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientClassComposer.java
@@ -30,7 +30,6 @@
 import com.google.api.gax.rpc.ServerStreamingCallable;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.api.generator.engine.ast.AnnotationNode;
-import com.google.api.generator.engine.ast.AnonymousClassExpr;
 import com.google.api.generator.engine.ast.AssignmentExpr;
 import com.google.api.generator.engine.ast.CastExpr;
 import com.google.api.generator.engine.ast.ClassDefinition;
@@ -38,6 +37,7 @@
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.Expr;
 import com.google.api.generator.engine.ast.ExprStatement;
+import com.google.api.generator.engine.ast.LambdaExpr;
 import com.google.api.generator.engine.ast.MethodDefinition;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
 import com.google.api.generator.engine.ast.NewObjectExpr;
@@ -85,19 +85,21 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.Generated;
 
-public class ServiceClientClassComposer implements ClassComposer {
-  private static final ServiceClientClassComposer INSTANCE = new ServiceClientClassComposer();
+public abstract class AbstractServiceClientClassComposer implements ClassComposer {
   private static final String PAGED_RESPONSE_TYPE_NAME_PATTERN = "%sPagedResponse";
   private static final String CALLABLE_NAME_PATTERN = "%sCallable";
   private static final String PAGED_CALLABLE_NAME_PATTERN = "%sPagedCallable";
@@ -106,19 +108,20 @@ public class ServiceClientClassComposer implements ClassComposer {
   private static final Reference LIST_REFERENCE = ConcreteReference.withClazz(List.class);
   private static final Reference MAP_REFERENCE = ConcreteReference.withClazz(Map.class);
 
-  private static final TypeNode OBJECTS_TYPE =
-      TypeNode.withReference(ConcreteReference.withClazz(Objects.class));
-
   private enum CallableMethodKind {
     REGULAR,
     LRO,
     PAGED,
   }
 
-  private ServiceClientClassComposer() {}
+  private final TransportContext transportContext;
+
+  protected AbstractServiceClientClassComposer(TransportContext transportContext) {
+    this.transportContext = transportContext;
+  }
 
-  public static ServiceClientClassComposer instance() {
-    return INSTANCE;
+  protected TransportContext getTransportContext() {
+    return transportContext;
   }
 
   @Override
@@ -129,7 +132,7 @@ public GapicClass generate(GapicContext context, Service service) {
     String className = ClassNames.getServiceClientClassName(service);
     GapicClass.Kind kind = Kind.MAIN;
     String pakkage = service.pakkage();
-    boolean hasLroClient = hasLroMethods(service);
+    boolean hasLroClient = service.hasLroMethods();
 
     Map<String, List<String>> grpcRpcsToJavaMethodNames = new HashMap<>();
 
@@ -198,7 +201,7 @@ private static List<CommentStatement> createClassHeaderComments(
         service, classMethodSampleCode, credentialsSampleCode, endpointSampleCode);
   }
 
-  private static List<MethodDefinition> createClassMethods(
+  private List<MethodDefinition> createClassMethods(
       Service service,
       Map<String, Message> messageTypes,
       TypeStore typeStore,
@@ -216,23 +219,19 @@ private static List<MethodDefinition> createClassMethods(
     return methods;
   }
 
-  private static boolean hasLroMethods(Service service) {
-    for (Method method : service.methods()) {
-      if (method.hasLro()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  private static List<Statement> createFieldDeclarations(
+  private List<Statement> createFieldDeclarations(
       Service service, TypeStore typeStore, boolean hasLroClient) {
     Map<String, TypeNode> fieldNameToTypes = new HashMap<>();
     fieldNameToTypes.put(
         "settings", typeStore.get(ClassNames.getServiceSettingsClassName(service)));
     fieldNameToTypes.put("stub", typeStore.get(ClassNames.getServiceStubClassName(service)));
     if (hasLroClient) {
-      fieldNameToTypes.put("operationsClient", typeStore.get("OperationsClient"));
+      Iterator<String> opClientName = getTransportContext().operationsClientNames().iterator();
+      Iterator<TypeNode> opClientType = getTransportContext().operationsClientTypes().iterator();
+
+      while (opClientName.hasNext() && opClientType.hasNext()) {
+        fieldNameToTypes.put(opClientName.next(), opClientType.next());
+      }
     }
 
     return fieldNameToTypes.entrySet().stream()
@@ -352,17 +351,15 @@ private static List<MethodDefinition> createStaticCreatorMethods(
     return methods;
   }
 
-  private static List<MethodDefinition> createConstructorMethods(
+  private List<MethodDefinition> createConstructorMethods(
       Service service, TypeStore typeStore, boolean hasLroClient) {
     List<MethodDefinition> methods = new ArrayList<>();
     String thisClientName = ClassNames.getServiceClientClassName(service);
     String settingsName = ClassNames.getServiceSettingsClassName(service);
     TypeNode thisClassType = typeStore.get(thisClientName);
     TypeNode stubSettingsType = typeStore.get(ClassNames.getServiceStubSettingsClassName(service));
-    TypeNode operationsClientType = typeStore.get("OperationsClient");
     TypeNode exceptionType = typeStore.get("IOException");
 
-    TypeNode settingsType = typeStore.get(settingsName);
     VariableExpr settingsVarExpr =
         VariableExpr.withVariable(
             Variable.builder().setName("settings").setType(typeStore.get(settingsName)).build());
@@ -372,9 +369,6 @@ private static List<MethodDefinition> createConstructorMethods(
                 .setType(typeStore.get(ClassNames.getServiceStubClassName(service)))
                 .setName("stub")
                 .build());
-    VariableExpr operationsClientVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder().setType(operationsClientType).setName("operationsClient").build());
 
     // Create the ServiceClient(ServiceSettings settings) ctor.
     List<Expr> ctorAssignmentExprs = new ArrayList<>();
@@ -404,25 +398,10 @@ private static List<MethodDefinition> createConstructorMethods(
                     .build())
             .build());
 
-    Expr clientArgExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(stubVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
-            .setMethodName("getOperationsStub")
-            .build();
-    AssignmentExpr operationsClientAssignExpr =
-        AssignmentExpr.builder()
-            .setVariableExpr(
-                operationsClientVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
-            .setValueExpr(
-                MethodInvocationExpr.builder()
-                    .setStaticReferenceType(operationsClientType)
-                    .setMethodName("create")
-                    .setArguments(clientArgExpr)
-                    .setReturnType(operationsClientVarExpr.type())
-                    .build())
-            .build();
+    List<AssignmentExpr> operationsClientAssignExprs =
+        createOperationsClientAssignExprs(thisExpr, stubVarExpr);
     if (hasLroClient) {
-      ctorAssignmentExprs.add(operationsClientAssignExpr);
+      ctorAssignmentExprs.addAll(operationsClientAssignExprs);
     }
 
     methods.add(
@@ -453,7 +432,7 @@ private static List<MethodDefinition> createConstructorMethods(
             .setValueExpr(stubVarExpr)
             .build());
     if (hasLroClient) {
-      ctorAssignmentExprs.add(operationsClientAssignExpr);
+      ctorAssignmentExprs.addAll(operationsClientAssignExprs);
     }
     AnnotationNode betaAnnotation =
         AnnotationNode.builder()
@@ -476,15 +455,70 @@ private static List<MethodDefinition> createConstructorMethods(
     return methods;
   }
 
-  private static List<MethodDefinition> createGetterMethods(
+  private List<AssignmentExpr> createOperationsClientAssignExprs(
+      Expr thisExpr, VariableExpr stubVarExpr) {
+    List<AssignmentExpr> operationsClientAssignExprs = new ArrayList<>();
+
+    Iterator<TypeNode> opClientTypesIt = getTransportContext().operationsClientTypes().iterator();
+    Iterator<String> opClientNamesIt = getTransportContext().operationsClientNames().iterator();
+    Iterator<String> opStubNamesIt =
+        getTransportContext().transportOperationsStubNames().iterator();
+
+    while (opClientTypesIt.hasNext() && opClientNamesIt.hasNext() && opStubNamesIt.hasNext()) {
+      TypeNode operationsClientType = opClientTypesIt.next();
+      String opClientName = opClientNamesIt.next();
+      String opStubName = opStubNamesIt.next();
+
+      VariableExpr operationsClientVarExpr =
+          VariableExpr.withVariable(
+              Variable.builder().setType(operationsClientType).setName(opClientName).build());
+
+      String operationsStubGetterName =
+          String.format("get%s", JavaStyle.toUpperCamelCase(opStubName));
+
+      Expr clientArgExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(stubVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
+              .setMethodName(operationsStubGetterName)
+              .build();
+
+      AssignmentExpr operationsClientAssignExpr =
+          AssignmentExpr.builder()
+              .setVariableExpr(
+                  operationsClientVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
+              .setValueExpr(
+                  MethodInvocationExpr.builder()
+                      .setStaticReferenceType(operationsClientType)
+                      .setMethodName("create")
+                      .setArguments(clientArgExpr)
+                      .setReturnType(operationsClientVarExpr.type())
+                      .build())
+              .build();
+      operationsClientAssignExprs.add(operationsClientAssignExpr);
+    }
+
+    return operationsClientAssignExprs;
+  }
+
+  private List<MethodDefinition> createGetterMethods(
       Service service, TypeStore typeStore, boolean hasLroClient) {
     Map<String, TypeNode> methodNameToTypes = new LinkedHashMap<>();
     methodNameToTypes.put(
         "getSettings", typeStore.get(ClassNames.getServiceSettingsClassName(service)));
     methodNameToTypes.put("getStub", typeStore.get(ClassNames.getServiceStubClassName(service)));
-    String getOperationsClientMethodName = "getOperationsClient";
+
+    Set<String> getOperationsClientMethodNames = new HashSet<>();
+
     if (hasLroClient) {
-      methodNameToTypes.put(getOperationsClientMethodName, typeStore.get("OperationsClient"));
+      Iterator<String> opClientNamesIt = getTransportContext().operationsClientNames().iterator();
+      Iterator<TypeNode> opClientTypesIt = getTransportContext().operationsClientTypes().iterator();
+
+      while (opClientNamesIt.hasNext() && opClientTypesIt.hasNext()) {
+        String opClientMethodName =
+            String.format("get%s", JavaStyle.toUpperCamelCase(opClientNamesIt.next()));
+        getOperationsClientMethodNames.add(opClientMethodName);
+        methodNameToTypes.put(opClientMethodName, opClientTypesIt.next());
+      }
     }
     AnnotationNode betaStubAnnotation =
         AnnotationNode.builder()
@@ -500,7 +534,7 @@ private static List<MethodDefinition> createGetterMethods(
               TypeNode methodReturnType = e.getValue();
               String returnVariableName = JavaStyle.toLowerCamelCase(methodName.substring(3));
               MethodDefinition.Builder methodBuilder = MethodDefinition.builder();
-              if (methodName.equals(getOperationsClientMethodName)) {
+              if (getOperationsClientMethodNames.contains(methodName)) {
                 methodBuilder =
                     methodBuilder.setHeaderCommentStatements(
                         ServiceClientCommentComposer.GET_OPERATIONS_CLIENT_METHOD_COMMENT);
@@ -620,7 +654,6 @@ private static List<MethodDefinition> createMethodVariants(
                           lro.responseType().reference(), lro.metadataType().reference())));
     }
 
-    String methodInputTypeName = methodInputType.reference().name();
     for (List<MethodArgument> signature : method.methodSignatures()) {
       // Get the argument list.
       List<VariableExpr> arguments =
@@ -1042,7 +1075,7 @@ private static List<ClassDefinition> createNestedPagingClasses(
       }
       // Find the repeated field.
       Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
-      Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
+      Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
       Preconditions.checkNotNull(
           repeatedPagedResultsField,
           String.format(
@@ -1159,29 +1192,14 @@ private static ClassDefinition createNestedRpcPagedResponseClass(
     VariableExpr inputVarExpr =
         VariableExpr.withVariable(
             Variable.builder().setName("input").setType(methodPageType).build());
-    TypeNode anonClassType =
-        TypeNode.withReference(
-            ConcreteReference.builder()
-                .setClazz(ApiFunction.class)
-                .setGenerics(Arrays.asList(methodPageType.reference(), thisClassType.reference()))
-                .build());
+
+    // Overrides ApiFunction.apply.
+    // (https://github.com/googleapis/api-common-java/blob/debf25960dea0367b0d3b5e16d57d76c1d01947e/src/main/java/com/google/api/core/ApiFunction.java).
     Expr pageToTransformExpr =
-        AnonymousClassExpr.builder()
-            .setType(anonClassType)
-            .setMethods(
-                Arrays.asList(
-                    MethodDefinition.builder()
-                        .setIsOverride(true)
-                        .setScope(ScopeNode.PUBLIC)
-                        .setReturnType(thisClassType)
-                        .setName("apply")
-                        .setArguments(inputVarExpr.toBuilder().setIsDecl(true).build())
-                        .setReturnExpr(
-                            NewObjectExpr.builder()
-                                .setType(thisClassType)
-                                .setArguments(inputVarExpr)
-                                .build())
-                        .build()))
+        LambdaExpr.builder()
+            .setArguments(inputVarExpr.toBuilder().setIsDecl(true).build())
+            .setReturnExpr(
+                NewObjectExpr.builder().setType(thisClassType).setArguments(inputVarExpr).build())
             .build();
 
     // createAsync method - return expression.
@@ -1534,7 +1552,7 @@ static Expr createRequestBuilderExpr(
         rootFields.add(rootField);
       }
       Trie<Field> updatedTrie =
-          rootFieldToTrie.containsKey(rootField) ? rootFieldToTrie.get(rootField) : new Trie();
+          rootFieldToTrie.containsKey(rootField) ? rootFieldToTrie.get(rootField) : new Trie<>();
       List<Field> nestedFieldsWithChild = new ArrayList<>(arg.nestedFields());
       nestedFieldsWithChild.add(arg.field());
       updatedTrie.insert(nestedFieldsWithChild);
@@ -1633,7 +1651,7 @@ private static String typeToSetterMethodName(TypeNode type) {
   }
 
   private static TypeStore createTypes(Service service, Map<String, Message> messageTypes) {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             AbstractPagedListResponse.class,
             ApiFunction.class,
@@ -1690,8 +1708,6 @@ private static void createVaporTypes(Service service, TypeStore typeStore) {
           ClassNames.getServiceClientClassName(service));
     }
 
-    // LRO Gapic-generated types.
-    typeStore.put("com.google.longrunning", "OperationsClient");
     // Pagination types.
     typeStore.putAll(
         service.pakkage(),
@@ -1736,17 +1752,6 @@ private static boolean isProtoEmptyType(TypeNode type) {
         && type.reference().name().equals("Empty");
   }
 
-  private static void updateGapicMetadata(
-      GapicContext context, String protoPackage, String javaPackage) {
-    context.updateGapicMetadata(
-        context
-            .gapicMetadata()
-            .toBuilder()
-            .setProtoPackage(protoPackage)
-            .setLibraryPackage(javaPackage)
-            .build());
-  }
-
   private static void updateGapicMetadata(
       GapicContext context,
       Service service,
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientTestClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientTestClassComposer.java
index 7f45e974b3..1c49899d15 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientTestClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientTestClassComposer.java
@@ -20,28 +20,19 @@
 import com.google.api.gax.rpc.BidiStreamingCallable;
 import com.google.api.gax.rpc.ClientStreamingCallable;
 import com.google.api.gax.rpc.InvalidArgumentException;
-import com.google.api.gax.rpc.OperationCallSettings;
-import com.google.api.gax.rpc.PagedCallSettings;
-import com.google.api.gax.rpc.ServerStreamingCallSettings;
 import com.google.api.gax.rpc.ServerStreamingCallable;
 import com.google.api.gax.rpc.StatusCode;
-import com.google.api.gax.rpc.StreamingCallSettings;
-import com.google.api.gax.rpc.UnaryCallSettings;
 import com.google.api.generator.engine.ast.AnnotationNode;
 import com.google.api.generator.engine.ast.AssignmentExpr;
-import com.google.api.generator.engine.ast.CastExpr;
 import com.google.api.generator.engine.ast.ClassDefinition;
 import com.google.api.generator.engine.ast.CommentStatement;
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.EmptyLineStatement;
-import com.google.api.generator.engine.ast.EnumRefExpr;
 import com.google.api.generator.engine.ast.Expr;
 import com.google.api.generator.engine.ast.ExprStatement;
-import com.google.api.generator.engine.ast.InstanceofExpr;
 import com.google.api.generator.engine.ast.LineComment;
 import com.google.api.generator.engine.ast.MethodDefinition;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
-import com.google.api.generator.engine.ast.NewObjectExpr;
 import com.google.api.generator.engine.ast.PrimitiveValue;
 import com.google.api.generator.engine.ast.Reference;
 import com.google.api.generator.engine.ast.ScopeNode;
@@ -80,6 +71,7 @@
 import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.ExecutionException;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.Generated;
 import org.junit.After;
@@ -98,7 +90,7 @@ public abstract class AbstractServiceClientTestClassComposer implements ClassCom
 
   protected static final TypeStore FIXED_TYPESTORE = createStaticTypes();
   protected static final AnnotationNode TEST_ANNOTATION =
-        AnnotationNode.withType(FIXED_TYPESTORE.get("Test"));
+      AnnotationNode.withType(FIXED_TYPESTORE.get("Test"));
 
   private final TransportContext transportContext;
 
@@ -112,12 +104,14 @@ public TransportContext getTransportContext() {
 
   @Override
   public GapicClass generate(GapicContext context, Service service) {
+    return generate(ClassNames.getServiceClientTestClassName(service), context, service);
+  }
+
+  protected GapicClass generate(String className, GapicContext context, Service service) {
     Map<String, ResourceName> resourceNames = context.helperResourceNames();
-    Map<String, Message> messageTypes = context.messages();
     String pakkage = service.pakkage();
     TypeStore typeStore = new TypeStore();
     addDynamicTypes(context, service, typeStore);
-    String className = ClassNames.getServiceClientTestClassName(service);
     GapicClass.Kind kind = Kind.MAIN;
 
     Map<String, VariableExpr> classMemberVarExprs =
@@ -149,16 +143,35 @@ protected abstract Map<String, VariableExpr> createClassMemberVarExprs(
 
   protected List<Statement> createClassMemberFieldDecls(
       Map<String, VariableExpr> classMemberVarExprs) {
-    return classMemberVarExprs.values().stream()
-        .map(
-            v ->
-                ExprStatement.withExpr(
-                    v.toBuilder()
-                        .setIsDecl(true)
-                        .setScope(ScopeNode.PRIVATE)
-                        .setIsStatic(v.type().reference().name().startsWith("Mock"))
-                        .build()))
-        .collect(Collectors.toList());
+    Function<VariableExpr, Boolean> isMockVarExprFn =
+        v -> v.type().reference().name().startsWith("Mock");
+
+    // Ordering matters for pretty-printing and ensuring that test output is deterministic.
+    List<Statement> fieldDeclStatements = new ArrayList<>();
+
+    // Static fields go first.
+    fieldDeclStatements.addAll(
+        classMemberVarExprs.values().stream()
+            .filter(v -> isMockVarExprFn.apply(v))
+            .map(
+                v ->
+                    ExprStatement.withExpr(
+                        v.toBuilder()
+                            .setIsDecl(true)
+                            .setScope(ScopeNode.PRIVATE)
+                            .setIsStatic(true)
+                            .build()))
+            .collect(Collectors.toList()));
+
+    fieldDeclStatements.addAll(
+        classMemberVarExprs.values().stream()
+            .filter(v -> !isMockVarExprFn.apply(v))
+            .map(
+                v ->
+                    ExprStatement.withExpr(
+                        v.toBuilder().setIsDecl(true).setScope(ScopeNode.PRIVATE).build()))
+            .collect(Collectors.toList()));
+    return fieldDeclStatements;
   }
 
   private List<MethodDefinition> createClassMethods(
@@ -180,7 +193,8 @@ private List<MethodDefinition> createTestAdminMethods(
       TypeStore typeStore) {
     List<MethodDefinition> javaMethods = new ArrayList<>();
     javaMethods.add(
-        createStartStaticServerMethod(service, context, classMemberVarExprs, typeStore));
+        createStartStaticServerMethod(
+            service, context, classMemberVarExprs, typeStore, "newBuilder"));
     javaMethods.add(createStopServerMethod(service, classMemberVarExprs));
     javaMethods.add(createSetUpMethod(service, classMemberVarExprs, typeStore));
     javaMethods.add(createTearDownMethod(service, classMemberVarExprs));
@@ -191,7 +205,8 @@ protected abstract MethodDefinition createStartStaticServerMethod(
       Service service,
       GapicContext context,
       Map<String, VariableExpr> classMemberVarExprs,
-      TypeStore typeStore);
+      TypeStore typeStore,
+      String newBuilderMethod);
 
   protected abstract MethodDefinition createStopServerMethod(
       Service service, Map<String, VariableExpr> classMemberVarExprs);
@@ -317,15 +332,21 @@ private MethodDefinition createRpcTestMethod(
     String mockServiceVarName = getMockServiceVarName(rpcService);
     if (method.isPaged()) {
       Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
-      Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
+      Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
       Preconditions.checkNotNull(
           repeatedPagedResultsField,
           String.format(
               "No repeated field found for paged method %s with output message type %s",
               method.name(), methodOutputMessage.name()));
 
-      // Must be a non-repeated type.
-      repeatedResponseType = repeatedPagedResultsField.type();
+      if (repeatedPagedResultsField.isMap()) {
+        repeatedResponseType =
+            TypeNode.withReference(repeatedPagedResultsField.type().reference().generics().get(1));
+      } else {
+        // Must be a non-repeated type.
+        repeatedResponseType = repeatedPagedResultsField.type();
+      }
+
       responsesElementVarExpr =
           VariableExpr.withVariable(
               Variable.builder().setType(repeatedResponseType).setName("responsesElement").build());
@@ -348,7 +369,7 @@ private MethodDefinition createRpcTestMethod(
     Expr expectedResponseValExpr = null;
     if (method.isPaged()) {
       Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
-      Field firstRepeatedField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
+      Field firstRepeatedField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
       Preconditions.checkNotNull(
           firstRepeatedField,
           String.format(
@@ -357,7 +378,10 @@ private MethodDefinition createRpcTestMethod(
 
       expectedResponseValExpr =
           DefaultValueComposer.createSimplePagedResponse(
-              method.outputType(), firstRepeatedField.name(), responsesElementVarExpr);
+              method.outputType(),
+              firstRepeatedField.name(),
+              responsesElementVarExpr,
+              firstRepeatedField.isMap());
     } else {
       if (messageTypes.containsKey(methodOutputType.reference().fullName())) {
         expectedResponseValExpr =
@@ -445,7 +469,7 @@ private MethodDefinition createRpcTestMethod(
             VariableExpr.withVariable(
                 Variable.builder().setType(methodArg.type()).setName(methodArgName).build());
         argExprs.add(varExpr);
-        Expr valExpr = DefaultValueComposer.createDefaultValue(methodArg, resourceNames);
+        Expr valExpr = createDefaultValue(methodArg, resourceNames);
         methodExprs.add(
             AssignmentExpr.builder()
                 .setVariableExpr(varExpr.toBuilder().setIsDecl(true).build())
@@ -500,6 +524,9 @@ private MethodDefinition createRpcTestMethod(
     }
 
     if (method.isPaged()) {
+      Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
+      Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
+
       // Assign the resources variable.
       VariableExpr resourcesVarExpr =
           VariableExpr.withVariable(
@@ -508,7 +535,8 @@ private MethodDefinition createRpcTestMethod(
                       TypeNode.withReference(
                           ConcreteReference.builder()
                               .setClazz(List.class)
-                              .setGenerics(Arrays.asList(repeatedResponseType.reference()))
+                              .setGenerics(
+                                  Arrays.asList(repeatedPagedResultsField.type().reference()))
                               .build()))
                   .setName("resources")
                   .build());
@@ -554,8 +582,6 @@ private MethodDefinition createRpcTestMethod(
               .build());
 
       // Assert the responses are equivalent.
-      Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
-      Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
       Preconditions.checkNotNull(
           repeatedPagedResultsField,
           String.format(
@@ -564,19 +590,52 @@ private MethodDefinition createRpcTestMethod(
 
       Expr zeroExpr =
           ValueExpr.withValue(PrimitiveValue.builder().setType(TypeNode.INT).setValue("0").build());
-      Expr expectedPagedResponseExpr =
-          MethodInvocationExpr.builder()
-              .setExprReferenceExpr(expectedResponseVarExpr)
-              .setMethodName(
-                  String.format(
-                      "get%sList", JavaStyle.toUpperCamelCase(repeatedPagedResultsField.name())))
-              .build();
-      expectedPagedResponseExpr =
-          MethodInvocationExpr.builder()
-              .setExprReferenceExpr(expectedPagedResponseExpr)
-              .setMethodName("get")
-              .setArguments(zeroExpr)
-              .build();
+
+      // Generated code:
+      // Assert.assertEquals(
+      //   expectedResponse.getItemsMap().entrySet().iterator().next(), resources.get(0));
+      // )
+      Expr expectedPagedResponseExpr;
+      if (repeatedPagedResultsField.isMap()) {
+        expectedPagedResponseExpr =
+            MethodInvocationExpr.builder()
+                .setMethodName("next")
+                .setExprReferenceExpr(
+                    MethodInvocationExpr.builder()
+                        .setMethodName("iterator")
+                        .setExprReferenceExpr(
+                            MethodInvocationExpr.builder()
+                                .setMethodName("entrySet")
+                                .setExprReferenceExpr(
+                                    MethodInvocationExpr.builder()
+                                        .setExprReferenceExpr(expectedResponseVarExpr)
+                                        .setMethodName(
+                                            String.format(
+                                                "get%sMap",
+                                                JavaStyle.toUpperCamelCase(
+                                                    repeatedPagedResultsField.name())))
+                                        .build())
+                                .build())
+                        .build())
+                .build();
+
+      } else {
+        // Generated code:
+        // Assert.assertEquals(expectedResponse.getItemsList().get(0), resources.get(0));
+        expectedPagedResponseExpr =
+            MethodInvocationExpr.builder()
+                .setExprReferenceExpr(expectedResponseVarExpr)
+                .setMethodName(
+                    String.format(
+                        "get%sList", JavaStyle.toUpperCamelCase(repeatedPagedResultsField.name())))
+                .build();
+        expectedPagedResponseExpr =
+            MethodInvocationExpr.builder()
+                .setExprReferenceExpr(expectedPagedResponseExpr)
+                .setMethodName("get")
+                .setArguments(zeroExpr)
+                .build();
+      }
       Expr actualPagedResponseExpr =
           MethodInvocationExpr.builder()
               .setExprReferenceExpr(resourcesVarExpr)
@@ -675,6 +734,9 @@ protected abstract List<Statement> createStreamingRpcExceptionTestStatements(
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes);
 
+  protected abstract Expr createDefaultValue(
+      MethodArgument methodArg, Map<String, ResourceName> resourceNames);
+
   protected List<Statement> createRpcExceptionTestStatements(
       Method method,
       List<MethodArgument> methodSignature,
@@ -706,7 +768,7 @@ protected List<Statement> createRpcExceptionTestStatements(
             VariableExpr.withVariable(
                 Variable.builder().setType(methodArg.type()).setName(methodArgName).build());
         argVarExprs.add(varExpr);
-        Expr valExpr = DefaultValueComposer.createDefaultValue(methodArg, resourceNames);
+        Expr valExpr = createDefaultValue(methodArg, resourceNames);
         tryBodyExprs.add(
             AssignmentExpr.builder()
                 .setVariableExpr(varExpr.toBuilder().setIsDecl(true).build())
@@ -765,8 +827,7 @@ protected List<Statement> createRpcExceptionTestStatements(
                 tryBodyExprs.stream()
                     .map(e -> ExprStatement.withExpr(e))
                     .collect(Collectors.toList()))
-            .setCatchVariableExpr(catchExceptionVarExpr.toBuilder().setIsDecl(true).build())
-            .setCatchBody(catchBody)
+            .addCatch(catchExceptionVarExpr.toBuilder().setIsDecl(true).build(), catchBody)
             .build();
 
     return Arrays.asList(EMPTY_LINE_STATEMENT, tryCatchBlock);
@@ -781,7 +842,7 @@ protected abstract List<Statement> createRpcLroExceptionTestCatchBody(
    */
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             AbstractMessage.class,
             After.class,
@@ -816,8 +877,10 @@ private void addDynamicTypes(GapicContext context, Service service, TypeStore ty
         Arrays.asList(
             ClassNames.getMockServiceClassName(service),
             ClassNames.getServiceClientClassName(service),
-            ClassNames.getServiceSettingsClassName(service),
-            getTransportContext().classNames().getTransportServiceStubClassName(service)));
+            ClassNames.getServiceSettingsClassName(service)));
+    String stubPakkage = String.format("%s.stub", service.pakkage());
+    typeStore.put(
+        stubPakkage, getTransportContext().classNames().getTransportServiceStubClassName(service));
     // Pagination types.
     typeStore.putAll(
         service.pakkage(),
@@ -842,70 +905,12 @@ private void addDynamicTypes(GapicContext context, Service service, TypeStore ty
     }
   }
 
-  private static TypeNode getOperationCallSettingsTypeHelper(
-      Method protoMethod, boolean isBuilder) {
-    Preconditions.checkState(
-        protoMethod.hasLro(),
-        String.format("Cannot get OperationCallSettings on non-LRO method %s", protoMethod.name()));
-    Class callSettingsClazz =
-        isBuilder ? OperationCallSettings.Builder.class : OperationCallSettings.class;
-    return TypeNode.withReference(
-        ConcreteReference.builder()
-            .setClazz(callSettingsClazz)
-            .setGenerics(
-                Arrays.asList(
-                    protoMethod.inputType().reference(),
-                    protoMethod.lro().responseType().reference(),
-                    protoMethod.lro().metadataType().reference()))
-            .build());
-  }
-
-  private static TypeNode getCallSettingsTypeHelper(
-      Method protoMethod, TypeStore typeStore, boolean isBuilder) {
-    Class callSettingsClazz = isBuilder ? UnaryCallSettings.Builder.class : UnaryCallSettings.class;
-    if (protoMethod.isPaged()) {
-      callSettingsClazz = isBuilder ? PagedCallSettings.Builder.class : PagedCallSettings.class;
-    } else {
-      switch (protoMethod.stream()) {
-        case CLIENT:
-          // Fall through.
-        case BIDI:
-          callSettingsClazz =
-              isBuilder ? StreamingCallSettings.Builder.class : StreamingCallSettings.class;
-          break;
-        case SERVER:
-          callSettingsClazz =
-              isBuilder
-                  ? ServerStreamingCallSettings.Builder.class
-                  : ServerStreamingCallSettings.class;
-          break;
-        case NONE:
-          // Fall through
-        default:
-          // Fall through
-      }
-    }
-
-    List<Reference> generics = new ArrayList<>();
-    generics.add(protoMethod.inputType().reference());
-    generics.add(protoMethod.outputType().reference());
-    if (protoMethod.isPaged()) {
-      generics.add(
-          typeStore
-              .get(String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, protoMethod.name()))
-              .reference());
-    }
-
-    return TypeNode.withReference(
-        ConcreteReference.builder().setClazz(callSettingsClazz).setGenerics(generics).build());
-  }
-
   protected static TypeNode getCallableType(Method protoMethod) {
     Preconditions.checkState(
         !protoMethod.stream().equals(Method.Stream.NONE),
         "No callable type exists for non-streaming methods.");
 
-    Class callableClazz = ClientStreamingCallable.class;
+    Class<?> callableClazz = ClientStreamingCallable.class;
     switch (protoMethod.stream()) {
       case BIDI:
         callableClazz = BidiStreamingCallable.class;
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceSettingsClassComposer.java
index 14e79caab9..ccf15a1d64 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceSettingsClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceSettingsClassComposer.java
@@ -62,11 +62,13 @@
 import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
 import com.google.longrunning.Operation;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
 import java.util.function.BiFunction;
@@ -172,6 +174,7 @@ private List<MethodDefinition> createClassMethods(Service service, TypeStore typ
     javaMethods.addAll(createSettingsGetterMethods(service, typeStore));
     javaMethods.add(createCreatorMethod(service, typeStore));
     javaMethods.addAll(createDefaultGetterMethods(service, typeStore));
+    javaMethods.addAll(createNewBuilderMethods(service, typeStore, "newBuilder", "createDefault"));
     javaMethods.addAll(createBuilderHelperMethods(service, typeStore));
     javaMethods.add(createConstructorMethod(service, typeStore));
     return javaMethods;
@@ -321,7 +324,7 @@ private List<MethodDefinition> createDefaultGetterMethods(Service service, TypeS
                         .build());
     BiFunction<MethodDefinition.Builder, CommentStatement, MethodDefinition> methodMakerFn =
         (methodDefBuilder, comment) -> methodDefBuilder.setHeaderCommentStatements(comment).build();
-    Function<Class, TypeNode> typeMakerFn =
+    Function<Class<?>, TypeNode> typeMakerFn =
         c -> TypeNode.withReference(ConcreteReference.withClazz(c));
 
     List<MethodDefinition> javaMethods = new ArrayList<>();
@@ -351,12 +354,19 @@ private List<MethodDefinition> createDefaultGetterMethods(Service service, TypeS
                 "defaultCredentialsProviderBuilder",
                 typeMakerFn.apply(GoogleCredentialsProvider.Builder.class)),
             SettingsCommentComposer.DEFAULT_CREDENTIALS_PROVIDER_BUILDER_METHOD_COMMENT));
-    javaMethods.add(
-        methodMakerFn.apply(
-            methodStarterFn.apply(
-                getTransportContext().defaultTransportProviderBuilderName(),
-                typeMakerFn.apply(getTransportContext().instantiatingChannelProviderClass())),
-            SettingsCommentComposer.DEFAULT_TRANSPORT_PROVIDER_BUILDER_METHOD_COMMENT));
+
+    Iterator<String> providerBuilderNamesIt =
+        getTransportContext().defaultTransportProviderBuilderNames().iterator();
+    Iterator<Class<?>> channelProviderClassesIt =
+        getTransportContext().instantiatingChannelProviderBuilderClasses().iterator();
+    while (providerBuilderNamesIt.hasNext() && channelProviderClassesIt.hasNext()) {
+      javaMethods.add(
+          methodMakerFn.apply(
+              methodStarterFn.apply(
+                  providerBuilderNamesIt.next(),
+                  typeMakerFn.apply(channelProviderClassesIt.next())),
+              SettingsCommentComposer.DEFAULT_TRANSPORT_PROVIDER_BUILDER_METHOD_COMMENT));
+    }
 
     javaMethods.add(
         methodStarterFn
@@ -383,23 +393,31 @@ private List<MethodDefinition> createDefaultGetterMethods(Service service, TypeS
     return javaMethods;
   }
 
-  private static List<MethodDefinition> createBuilderHelperMethods(
-      Service service, TypeStore typeStore) {
+  protected List<MethodDefinition> createNewBuilderMethods(
+      Service service,
+      TypeStore typeStore,
+      String newBuilderMethodName,
+      String createDefaultMethodName) {
     TypeNode builderType = typeStore.get(BUILDER_CLASS_NAME);
-    MethodDefinition newBuilderMethodOne =
+    return ImmutableList.of(
         MethodDefinition.builder()
             .setHeaderCommentStatements(SettingsCommentComposer.NEW_BUILDER_METHOD_COMMENT)
             .setScope(ScopeNode.PUBLIC)
             .setIsStatic(true)
             .setReturnType(builderType)
-            .setName("newBuilder")
+            .setName(newBuilderMethodName)
             .setReturnExpr(
                 MethodInvocationExpr.builder()
                     .setStaticReferenceType(builderType)
-                    .setMethodName("createDefault")
+                    .setMethodName(createDefaultMethodName)
                     .setReturnType(builderType)
                     .build())
-            .build();
+            .build());
+  }
+
+  private static List<MethodDefinition> createBuilderHelperMethods(
+      Service service, TypeStore typeStore) {
+    TypeNode builderType = typeStore.get(BUILDER_CLASS_NAME);
 
     VariableExpr clientContextVarExpr =
         VariableExpr.withVariable(
@@ -439,10 +457,10 @@ private static List<MethodDefinition> createBuilderHelperMethods(
                     .build())
             .build();
 
-    return Arrays.asList(newBuilderMethodOne, newBuilderMethodTwo, toBuilderMethod);
+    return Arrays.asList(newBuilderMethodTwo, toBuilderMethod);
   }
 
-  private static ClassDefinition createNestedBuilderClass(Service service, TypeStore typeStore) {
+  private ClassDefinition createNestedBuilderClass(Service service, TypeStore typeStore) {
     return ClassDefinition.builder()
         .setHeaderCommentStatements(
             SettingsCommentComposer.createBuilderClassComment(
@@ -466,11 +484,12 @@ private static ClassDefinition createNestedBuilderClass(Service service, TypeSto
         .build();
   }
 
-  private static List<MethodDefinition> createNestedBuilderClassMethods(
+  private List<MethodDefinition> createNestedBuilderClassMethods(
       Service service, TypeStore typeStore) {
     List<MethodDefinition> javaMethods = new ArrayList<>();
     javaMethods.addAll(createNestedBuilderConstructorMethods(service, typeStore));
-    javaMethods.add(createNestedBuilderCreatorMethod(service, typeStore));
+    javaMethods.addAll(
+        createNestedBuilderCreatorMethods(service, typeStore, "newBuilder", "createDefault"));
     javaMethods.add(createNestedBuilderStubSettingsBuilderMethod(service, typeStore));
     javaMethods.add(createNestedBuilderApplyToAllUnaryMethod(service, typeStore));
     javaMethods.addAll(createNestedBuilderSettingsGetterMethods(service, typeStore));
@@ -557,23 +576,28 @@ private static List<MethodDefinition> createNestedBuilderConstructorMethods(
     return Arrays.asList(noArgCtor, clientContextCtor, settingsCtor, stubSettingsCtor);
   }
 
-  private static MethodDefinition createNestedBuilderCreatorMethod(
-      Service service, TypeStore typeStore) {
+  protected List<MethodDefinition> createNestedBuilderCreatorMethods(
+      Service service,
+      TypeStore typeStore,
+      String newBuilderMethodName,
+      String createDefaultMethodName) {
     MethodInvocationExpr ctorArg =
         MethodInvocationExpr.builder()
             .setStaticReferenceType(
                 typeStore.get(ClassNames.getServiceStubSettingsClassName(service)))
-            .setMethodName("newBuilder")
+            .setMethodName(newBuilderMethodName)
             .build();
 
     TypeNode builderType = typeStore.get(BUILDER_CLASS_NAME);
-    return MethodDefinition.builder()
-        .setScope(ScopeNode.PRIVATE)
-        .setIsStatic(true)
-        .setReturnType(builderType)
-        .setName("createDefault")
-        .setReturnExpr(NewObjectExpr.builder().setType(builderType).setArguments(ctorArg).build())
-        .build();
+    return ImmutableList.of(
+        MethodDefinition.builder()
+            .setScope(ScopeNode.PRIVATE)
+            .setIsStatic(true)
+            .setReturnType(builderType)
+            .setName(createDefaultMethodName)
+            .setReturnExpr(
+                NewObjectExpr.builder().setType(builderType).setArguments(ctorArg).build())
+            .build());
   }
 
   private static MethodDefinition createNestedBuilderStubSettingsBuilderMethod(
@@ -648,8 +672,6 @@ private static MethodDefinition createNestedBuilderApplyToAllUnaryMethod(
         .setReturnType(builderType)
         .setName(javaMethodName)
         .setArguments(Arrays.asList(settingsUpdaterVarExpr.toBuilder().setIsDecl(true).build()))
-        .setThrowsExceptions(
-            Arrays.asList(TypeNode.withReference(ConcreteReference.withClazz(Exception.class))))
         .setBody(Arrays.asList(ExprStatement.withExpr(applyMethodExpr)))
         .setReturnExpr(ValueExpr.withValue(ThisObjectValue.withType(builderType)))
         .build();
@@ -728,7 +750,7 @@ private static MethodDefinition createNestedBuilderClassBuildMethod(
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             ApiClientHeaderProvider.class,
             ApiFunction.class,
@@ -793,7 +815,7 @@ private static TypeNode getOperationCallSettingsTypeHelper(
     Preconditions.checkState(
         protoMethod.hasLro(),
         String.format("Cannot get OperationCallSettings on non-LRO method %s", protoMethod.name()));
-    Class callSettingsClazz =
+    Class<?> callSettingsClazz =
         isBuilder ? OperationCallSettings.Builder.class : OperationCallSettings.class;
     return TypeNode.withReference(
         ConcreteReference.builder()
@@ -816,7 +838,8 @@ private static TypeNode getCallSettingsBuilderType(Method protoMethod, TypeStore
 
   private static TypeNode getCallSettingsTypeHelper(
       Method protoMethod, TypeStore typeStore, boolean isBuilder) {
-    Class callSettingsClazz = isBuilder ? UnaryCallSettings.Builder.class : UnaryCallSettings.class;
+    Class<?> callSettingsClazz =
+        isBuilder ? UnaryCallSettings.Builder.class : UnaryCallSettings.class;
     if (protoMethod.isPaged()) {
       callSettingsClazz = isBuilder ? PagedCallSettings.Builder.class : PagedCallSettings.class;
     } else if (protoMethod.isBatching()) {
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubClassComposer.java
index 4b6e8555b1..3f80382bab 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubClassComposer.java
@@ -16,75 +16,42 @@
 
 import com.google.api.core.BetaApi;
 import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.core.BackgroundResourceAggregation;
 import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.ClientStreamingCallable;
 import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.ServerStreamingCallable;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.api.generator.engine.ast.AnnotationNode;
-import com.google.api.generator.engine.ast.AssignmentExpr;
 import com.google.api.generator.engine.ast.ClassDefinition;
-import com.google.api.generator.engine.ast.CommentStatement;
-import com.google.api.generator.engine.ast.ConcreteReference;
-import com.google.api.generator.engine.ast.EmptyLineStatement;
-import com.google.api.generator.engine.ast.Expr;
 import com.google.api.generator.engine.ast.ExprStatement;
-import com.google.api.generator.engine.ast.JavaDocComment;
 import com.google.api.generator.engine.ast.MethodDefinition;
-import com.google.api.generator.engine.ast.MethodInvocationExpr;
-import com.google.api.generator.engine.ast.NewObjectExpr;
-import com.google.api.generator.engine.ast.ReferenceConstructorExpr;
+import com.google.api.generator.engine.ast.Reference;
 import com.google.api.generator.engine.ast.ScopeNode;
-import com.google.api.generator.engine.ast.Statement;
-import com.google.api.generator.engine.ast.ThisObjectValue;
+import com.google.api.generator.engine.ast.ThrowExpr;
 import com.google.api.generator.engine.ast.TypeNode;
-import com.google.api.generator.engine.ast.ValueExpr;
-import com.google.api.generator.engine.ast.Variable;
-import com.google.api.generator.engine.ast.VariableExpr;
 import com.google.api.generator.gapic.composer.comment.StubCommentComposer;
 import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.composer.utils.ClassNames;
 import com.google.api.generator.gapic.composer.utils.PackageChecker;
 import com.google.api.generator.gapic.model.GapicClass;
 import com.google.api.generator.gapic.model.GapicClass.Kind;
 import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.Method;
 import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.utils.JavaStyle;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
 import com.google.longrunning.Operation;
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.LinkedHashMap;
+import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.TimeUnit;
-import java.util.function.BiFunction;
-import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.Generated;
 
 public abstract class AbstractServiceStubClassComposer implements ClassComposer {
-  private static final Statement EMPTY_LINE_STATEMENT = EmptyLineStatement.create();
-
-  private static final String METHOD_DESCRIPTOR_NAME_PATTERN = "%sMethodDescriptor";
   private static final String PAGED_RESPONSE_TYPE_NAME_PATTERN = "%sPagedResponse";
-  private static final String PAGED_CALLABLE_CLASS_MEMBER_PATTERN = "%sPagedCallable";
-
-  private static final String BACKGROUND_RESOURCES_MEMBER_NAME = "backgroundResources";
-  private static final String CALLABLE_NAME = "Callable";
-  private static final String CALLABLE_FACTORY_MEMBER_NAME = "callableFactory";
-  private static final String CALLABLE_CLASS_MEMBER_PATTERN = "%sCallable";
-  private static final String OPERATION_CALLABLE_CLASS_MEMBER_PATTERN = "%sOperationCallable";
-  private static final String OPERATION_CALLABLE_NAME = "OperationCallable";
-  private static final String OPERATIONS_STUB_MEMBER_NAME = "operationsStub";
-  private static final String PAGED_CALLABLE_NAME = "PagedCallable";
-
-  protected static final TypeStore FIXED_TYPESTORE = createStaticTypes();
 
   private final TransportContext transportContext;
 
@@ -92,252 +59,38 @@ protected AbstractServiceStubClassComposer(TransportContext transportContext) {
     this.transportContext = transportContext;
   }
 
-  public TransportContext getTransportContext() {
+  protected TransportContext getTransportContext() {
     return transportContext;
   }
 
-  private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
-        Arrays.asList(
-            BackgroundResource.class,
-            BackgroundResourceAggregation.class,
-            BetaApi.class,
-            BidiStreamingCallable.class,
-            ClientContext.class,
-            ClientStreamingCallable.class,
-            Generated.class,
-            ImmutableMap.class,
-            InterruptedException.class,
-            IOException.class,
-            Operation.class,
-            OperationCallable.class,
-            RequestParamsExtractor.class,
-            ServerStreamingCallable.class,
-            TimeUnit.class,
-            UnaryCallable.class);
-    return new TypeStore(concreteClazzes);
-  }
-
   @Override
   public GapicClass generate(GapicContext context, Service service) {
-    String pakkage = service.pakkage() + ".stub";
-    TypeStore typeStore = createDynamicTypes(service, pakkage);
-    String className = getTransportContext().classNames().getTransportServiceStubClassName(service);
+    Map<String, Message> messageTypes = context.messages();
+    TypeStore typeStore = createTypes(service, messageTypes);
+    String className = ClassNames.getServiceStubClassName(service);
     GapicClass.Kind kind = Kind.STUB;
-
-    Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs =
-        createProtoMethodNameToDescriptorClassMembers(
-            service, getTransportContext().methodDescriptorClass());
-
-    Map<String, VariableExpr> callableClassMemberVarExprs =
-        createCallableClassMembers(service, typeStore);
-
-    Map<String, VariableExpr> classMemberVarExprs = new LinkedHashMap<>();
-    classMemberVarExprs.put(
-        BACKGROUND_RESOURCES_MEMBER_NAME,
-        VariableExpr.withVariable(
-            Variable.builder()
-                .setName(BACKGROUND_RESOURCES_MEMBER_NAME)
-                .setType(FIXED_TYPESTORE.get("BackgroundResource"))
-                .build()));
-    if (getTransportContext().transportOperationsStubType() != null) {
-      classMemberVarExprs.put(
-          OPERATIONS_STUB_MEMBER_NAME,
-          VariableExpr.withVariable(
-              Variable.builder()
-                  .setName(OPERATIONS_STUB_MEMBER_NAME)
-                  .setType(getTransportContext().transportOperationsStubType())
-                  .build()));
-    }
-    classMemberVarExprs.put(
-        CALLABLE_FACTORY_MEMBER_NAME,
-        VariableExpr.withVariable(
-            Variable.builder()
-                .setName(CALLABLE_FACTORY_MEMBER_NAME)
-                .setType(getTransportContext().stubCallableFactoryType())
-                .build()));
-
-    List<Statement> classStatements =
-        createClassStatements(
-            service,
-            protoMethodNameToDescriptorVarExprs,
-            callableClassMemberVarExprs,
-            classMemberVarExprs);
-
-    StubCommentComposer commentComposer =
-        new StubCommentComposer(getTransportContext().transportName());
+    String pakkage = String.format("%s.stub", service.pakkage());
 
     ClassDefinition classDef =
         ClassDefinition.builder()
             .setPackageString(pakkage)
             .setHeaderCommentStatements(
-                commentComposer.createTransportServiceStubClassHeaderComments(
+                StubCommentComposer.createServiceStubClassHeaderComments(
                     service.name(), service.isDeprecated()))
-            .setAnnotations(createClassAnnotations(service))
-            .setScope(ScopeNode.PUBLIC)
+            .setAnnotations(createClassAnnotations(service, typeStore))
+            .setIsAbstract(true)
+            .setImplementsTypes(createClassImplements(typeStore))
             .setName(className)
-            .setExtendsType(
-                typeStore.get(getTransportContext().classNames().getServiceStubClassName(service)))
-            .setStatements(classStatements)
-            .setMethods(
-                createClassMethods(
-                    service,
-                    typeStore,
-                    classMemberVarExprs,
-                    callableClassMemberVarExprs,
-                    protoMethodNameToDescriptorVarExprs))
+            .setMethods(createClassMethods(service, messageTypes, typeStore))
+            .setScope(ScopeNode.PUBLIC)
             .build();
     return GapicClass.create(kind, classDef);
   }
 
-  protected abstract Statement createMethodDescriptorVariableDecl(
-      Service service, Method protoMethod, VariableExpr methodDescriptorVarExpr);
-
-  protected abstract List<MethodDefinition> createOperationsStubGetterMethod(
-      VariableExpr operationsStubVarExpr);
-
-  protected abstract Expr createTransportSettingsInitExpr(
-      Method method, VariableExpr transportSettingsVarExpr, VariableExpr methodDescriptorVarExpr);
-
-  protected List<MethodDefinition> createGetMethodDescriptorsMethod(
-      Service service,
-      TypeStore typeStore,
-      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
-    return Arrays.asList();
-  }
-
-  protected List<Statement> createClassStatements(
-      Service service,
-      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs,
-      Map<String, VariableExpr> callableClassMemberVarExprs,
-      Map<String, VariableExpr> classMemberVarExprs) {
-    List<Statement> classStatements = new ArrayList<>();
-    for (Statement statement :
-        createMethodDescriptorVariableDecls(service, protoMethodNameToDescriptorVarExprs)) {
-      classStatements.add(statement);
-      classStatements.add(EMPTY_LINE_STATEMENT);
-    }
-
-    classStatements.addAll(createClassMemberFieldDeclarations(callableClassMemberVarExprs));
-    classStatements.add(EMPTY_LINE_STATEMENT);
-
-    classStatements.addAll(createClassMemberFieldDeclarations(classMemberVarExprs));
-    return classStatements;
-  }
-
-  protected List<Statement> createMethodDescriptorVariableDecls(
-      Service service, Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
-    return service.methods().stream()
-        .map(
-            m ->
-                createMethodDescriptorVariableDecl(
-                    service, m, protoMethodNameToDescriptorVarExprs.get(m.name())))
-        .collect(Collectors.toList());
-  }
-
-  private static List<Statement> createClassMemberFieldDeclarations(
-      Map<String, VariableExpr> fieldNameToVarExprs) {
-    return fieldNameToVarExprs.values().stream()
-        .map(
-            v ->
-                ExprStatement.withExpr(
-                    v.toBuilder()
-                        .setIsDecl(true)
-                        .setScope(ScopeNode.PRIVATE)
-                        .setIsFinal(true)
-                        .build()))
-        .collect(Collectors.toList());
-  }
-
-  protected Map<String, VariableExpr> createProtoMethodNameToDescriptorClassMembers(
-      Service service, Class<?> descriptorClass) {
-    return service.methods().stream()
-        .collect(
-            Collectors.toMap(
-                Method::name,
-                m ->
-                    VariableExpr.withVariable(
-                        Variable.builder()
-                            .setName(
-                                String.format(
-                                    METHOD_DESCRIPTOR_NAME_PATTERN,
-                                    JavaStyle.toLowerCamelCase(m.name())))
-                            .setType(
-                                TypeNode.withReference(
-                                    ConcreteReference.builder()
-                                        .setClazz(descriptorClass)
-                                        .setGenerics(
-                                            Arrays.asList(
-                                                m.inputType().reference(),
-                                                m.outputType().reference()))
-                                        .build()))
-                            .build())));
-  }
-
-  private Map<String, VariableExpr> createCallableClassMembers(
-      Service service, TypeStore typeStore) {
-    Map<String, VariableExpr> callableClassMembers = new LinkedHashMap<>();
-    // Using a for-loop because the output cardinality is not a 1:1 mapping to the input set.
-    for (Method protoMethod : service.methods()) {
-      String javaStyleProtoMethodName = JavaStyle.toLowerCamelCase(protoMethod.name());
-      String callableName = String.format(CALLABLE_CLASS_MEMBER_PATTERN, javaStyleProtoMethodName);
-      callableClassMembers.put(
-          callableName,
-          VariableExpr.withVariable(
-              Variable.builder()
-                  .setName(callableName)
-                  .setType(getCallableType(protoMethod))
-                  .build()));
-      if (protoMethod.hasLro()) {
-        callableName =
-            String.format(OPERATION_CALLABLE_CLASS_MEMBER_PATTERN, javaStyleProtoMethodName);
-        callableClassMembers.put(
-            callableName,
-            VariableExpr.withVariable(
-                Variable.builder()
-                    .setName(callableName)
-                    .setType(
-                        TypeNode.withReference(
-                            ConcreteReference.builder()
-                                .setClazz(OperationCallable.class)
-                                .setGenerics(
-                                    Arrays.asList(
-                                        protoMethod.inputType().reference(),
-                                        protoMethod.lro().responseType().reference(),
-                                        protoMethod.lro().metadataType().reference()))
-                                .build()))
-                    .build()));
-      }
-      if (protoMethod.isPaged()) {
-        callableName = String.format(PAGED_CALLABLE_CLASS_MEMBER_PATTERN, javaStyleProtoMethodName);
-        callableClassMembers.put(
-            callableName,
-            VariableExpr.withVariable(
-                Variable.builder()
-                    .setName(callableName)
-                    .setType(
-                        TypeNode.withReference(
-                            getCallableType(protoMethod)
-                                .reference()
-                                .copyAndSetGenerics(
-                                    Arrays.asList(
-                                        protoMethod.inputType().reference(),
-                                        typeStore
-                                            .get(
-                                                String.format(
-                                                    PAGED_RESPONSE_TYPE_NAME_PATTERN,
-                                                    protoMethod.name()))
-                                            .reference()))))
-                    .build()));
-      }
-    }
-    return callableClassMembers;
-  }
-
-  protected List<AnnotationNode> createClassAnnotations(Service service) {
+  private static List<AnnotationNode> createClassAnnotations(Service service, TypeStore typeStore) {
     List<AnnotationNode> annotations = new ArrayList<>();
     if (!PackageChecker.isGaApi(service.pakkage())) {
-      annotations.add(AnnotationNode.withType(FIXED_TYPESTORE.get("BetaApi")));
+      annotations.add(AnnotationNode.withType(typeStore.get("BetaApi")));
     }
 
     if (service.isDeprecated()) {
@@ -346,504 +99,153 @@ protected List<AnnotationNode> createClassAnnotations(Service service) {
 
     annotations.add(
         AnnotationNode.builder()
-            .setType(FIXED_TYPESTORE.get("Generated"))
+            .setType(typeStore.get("Generated"))
             .setDescription("by gapic-generator-java")
             .build());
     return annotations;
   }
 
-  protected List<MethodDefinition> createClassMethods(
-      Service service,
-      TypeStore typeStore,
-      Map<String, VariableExpr> classMemberVarExprs,
-      Map<String, VariableExpr> callableClassMemberVarExprs,
-      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
-    List<MethodDefinition> javaMethods = new ArrayList<>();
-    javaMethods.addAll(createStaticCreatorMethods(service, typeStore));
-    javaMethods.addAll(
-        createConstructorMethods(
-            service,
-            typeStore,
-            classMemberVarExprs,
-            callableClassMemberVarExprs,
-            protoMethodNameToDescriptorVarExprs));
-    javaMethods.addAll(
-        createGetMethodDescriptorsMethod(service, typeStore, protoMethodNameToDescriptorVarExprs));
-    javaMethods.addAll(
-        createOperationsStubGetterMethod(classMemberVarExprs.get(OPERATIONS_STUB_MEMBER_NAME)));
-    javaMethods.addAll(createCallableGetterMethods(callableClassMemberVarExprs));
-    javaMethods.addAll(
-        createStubOverrideMethods(classMemberVarExprs.get(BACKGROUND_RESOURCES_MEMBER_NAME)));
-    return javaMethods;
+  private static List<TypeNode> createClassImplements(TypeStore typeStore) {
+    return Arrays.asList(typeStore.get("BackgroundResource"));
   }
 
-  private List<MethodDefinition> createStaticCreatorMethods(Service service, TypeStore typeStore) {
-    TypeNode creatorMethodReturnType =
-        typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service));
-    Function<List<VariableExpr>, MethodDefinition.Builder> creatorMethodStarterFn =
-        argList ->
-            MethodDefinition.builder()
-                .setScope(ScopeNode.PUBLIC)
-                .setIsStatic(true)
-                .setIsFinal(true)
-                .setReturnType(creatorMethodReturnType)
-                .setName("create")
-                .setArguments(
-                    argList.stream()
-                        .map(v -> v.toBuilder().setIsDecl(true).build())
-                        .collect(Collectors.toList()))
-                .setThrowsExceptions(
-                    Arrays.asList(
-                        TypeNode.withReference(ConcreteReference.withClazz(IOException.class))));
-
-    Function<List<Expr>, Expr> instantiatorExprFn =
-        argList ->
-            NewObjectExpr.builder().setType(creatorMethodReturnType).setArguments(argList).build();
-
-    TypeNode stubSettingsType =
-        typeStore.get(getTransportContext().classNames().getServiceStubSettingsClassName(service));
-    VariableExpr settingsVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder().setName("settings").setType(stubSettingsType).build());
-
-    TypeNode clientContextType = FIXED_TYPESTORE.get("ClientContext");
-    VariableExpr clientContextVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder().setName("clientContext").setType(clientContextType).build());
-
-    VariableExpr callableFactoryVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder()
-                .setName("callableFactory")
-                .setType(getTransportContext().stubCallableFactoryType())
-                .build());
-
-    MethodInvocationExpr clientContextCreateMethodExpr =
-        MethodInvocationExpr.builder()
-            .setMethodName("create")
-            .setStaticReferenceType(clientContextType)
-            .setArguments(Arrays.asList(settingsVarExpr))
-            .build();
-    MethodInvocationExpr settingsBuilderMethodExpr =
-        MethodInvocationExpr.builder()
-            .setMethodName("newBuilder")
-            .setStaticReferenceType(stubSettingsType)
-            .build();
-    settingsBuilderMethodExpr =
-        MethodInvocationExpr.builder()
-            .setMethodName("build")
-            .setExprReferenceExpr(settingsBuilderMethodExpr)
-            .build();
-
-    return Arrays.asList(
-        creatorMethodStarterFn
-            .apply(Arrays.asList(settingsVarExpr))
-            .setReturnExpr(
-                instantiatorExprFn.apply(
-                    Arrays.asList(settingsVarExpr, clientContextCreateMethodExpr)))
-            .build(),
-        creatorMethodStarterFn
-            .apply(Arrays.asList(clientContextVarExpr))
-            .setReturnExpr(
-                instantiatorExprFn.apply(
-                    Arrays.asList(settingsBuilderMethodExpr, clientContextVarExpr)))
-            .build(),
-        creatorMethodStarterFn
-            .apply(Arrays.asList(clientContextVarExpr, callableFactoryVarExpr))
-            .setReturnExpr(
-                instantiatorExprFn.apply(
-                    Arrays.asList(
-                        settingsBuilderMethodExpr, clientContextVarExpr, callableFactoryVarExpr)))
-            .build());
+  private List<MethodDefinition> createClassMethods(
+      Service service, Map<String, Message> messageTypes, TypeStore typeStore) {
+    boolean hasLroClient = service.hasLroMethods();
+    List<MethodDefinition> methods = new ArrayList<>();
+    if (hasLroClient) {
+      methods.addAll(createOperationsStubGetters(typeStore));
+    }
+    methods.addAll(createCallableGetters(service, messageTypes, typeStore));
+    methods.addAll(createBackgroundResourceMethodOverrides());
+    return methods;
   }
 
-  protected List<MethodDefinition> createConstructorMethods(
-      Service service,
-      TypeStore typeStore,
-      Map<String, VariableExpr> classMemberVarExprs,
-      Map<String, VariableExpr> callableClassMemberVarExprs,
-      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
-    TypeNode stubSettingsType =
-        typeStore.get(getTransportContext().classNames().getServiceStubSettingsClassName(service));
-    VariableExpr settingsVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder().setName("settings").setType(stubSettingsType).build());
-
-    TypeNode clientContextType = FIXED_TYPESTORE.get("ClientContext");
-    VariableExpr clientContextVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder().setName("clientContext").setType(clientContextType).build());
-
-    VariableExpr callableFactoryVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder()
-                .setName("callableFactory")
-                .setType(getTransportContext().stubCallableFactoryType())
-                .build());
-
-    TypeNode thisClassType =
-        typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service));
-    TypeNode ioExceptionType =
-        TypeNode.withReference(ConcreteReference.withClazz(IOException.class));
-
-    BiFunction<List<VariableExpr>, List<Statement>, MethodDefinition> ctorMakerFn =
-        (args, body) ->
-            MethodDefinition.constructorBuilder()
-                .setScope(ScopeNode.PROTECTED)
-                .setReturnType(thisClassType)
-                .setHeaderCommentStatements(Arrays.asList(createProtectedCtorComment(service)))
-                .setArguments(
-                    args.stream()
-                        .map(v -> v.toBuilder().setIsDecl(true).build())
-                        .collect(Collectors.toList()))
-                .setThrowsExceptions(Arrays.asList(ioExceptionType))
-                .setBody(body)
-                .build();
-
-    // First constructor method.
-    MethodDefinition firstCtor =
-        ctorMakerFn.apply(
-            Arrays.asList(settingsVarExpr, clientContextVarExpr),
-            Arrays.asList(
-                ExprStatement.withExpr(
-                    ReferenceConstructorExpr.thisBuilder()
-                        .setType(thisClassType)
-                        .setArguments(
-                            settingsVarExpr,
-                            clientContextVarExpr,
-                            NewObjectExpr.builder()
-                                .setType(
-                                    typeStore.get(
-                                        getTransportContext()
-                                            .classNames()
-                                            .getTransportServiceCallableFactoryClassName(service)))
-                                .build())
-                        .build())));
-
-    Expr thisExpr =
-        ValueExpr.withValue(
-            ThisObjectValue.withType(
-                typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service))));
-    // Body of the second constructor method.
-    List<Statement> secondCtorStatements = new ArrayList<>();
-    List<Expr> secondCtorExprs = new ArrayList<>();
-    secondCtorExprs.add(
-        AssignmentExpr.builder()
-            .setVariableExpr(
-                classMemberVarExprs.get("callableFactory").toBuilder()
-                    .setExprReferenceExpr(thisExpr)
-                    .build())
-            .setValueExpr(callableFactoryVarExpr)
-            .build());
-    VariableExpr operationsStubClassVarExpr = classMemberVarExprs.get(OPERATIONS_STUB_MEMBER_NAME);
-    if (getTransportContext().transportOperationsStubType() != null) {
-      secondCtorExprs.add(
-          AssignmentExpr.builder()
-              .setVariableExpr(
-                  operationsStubClassVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
-              .setValueExpr(
-                  MethodInvocationExpr.builder()
-                      .setStaticReferenceType(
-                          getTransportContext().transportOperationsStubType())
-                      .setMethodName("create")
-                      .setArguments(Arrays.asList(clientContextVarExpr, callableFactoryVarExpr))
-                      .setReturnType(operationsStubClassVarExpr.type())
-                      .build())
-              .build());
+  private List<MethodDefinition> createCallableGetters(
+      Service service, Map<String, Message> messageTypes, TypeStore typeStore) {
+    // Use a traditional for-loop since the output cardinality is not necessarily 1:1 with that of
+    // service.methods().
+    List<MethodDefinition> javaMethods = new ArrayList<>();
+    for (Method method : service.methods()) {
+      if (method.hasLro()) {
+        javaMethods.add(createOperationCallableGetter(method, typeStore));
+      }
+      if (method.isPaged()) {
+        javaMethods.add(createPagedCallableGetter(method, typeStore));
+      }
+      javaMethods.add(createCallableGetter(method, typeStore));
     }
-    secondCtorStatements.addAll(
-        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
-    secondCtorExprs.clear();
-    secondCtorStatements.add(EMPTY_LINE_STATEMENT);
+    return javaMethods;
+  }
 
-    // Transport settings local variables.
-    Map<String, VariableExpr> javaStyleMethodNameToTransportSettingsVarExprs =
-        service.methods().stream()
-            .collect(
-                Collectors.toMap(
-                    m -> JavaStyle.toLowerCamelCase(m.name()),
-                    m ->
-                        VariableExpr.withVariable(
-                            Variable.builder()
-                                .setName(
-                                    String.format(
-                                        "%sTransportSettings",
-                                        JavaStyle.toLowerCamelCase(m.name())))
-                                .setType(
-                                    TypeNode.withReference(
-                                        ConcreteReference.builder()
-                                            .setClazz(getTransportContext().callSettingsClass())
-                                            .setGenerics(
-                                                Arrays.asList(
-                                                    m.inputType().reference(),
-                                                    m.outputType().reference()))
-                                            .build()))
-                                .build())));
-
-    secondCtorExprs.addAll(
-        service.methods().stream()
-            .map(
-                m ->
-                    createTransportSettingsInitExpr(
-                        m,
-                        javaStyleMethodNameToTransportSettingsVarExprs.get(
-                            JavaStyle.toLowerCamelCase(m.name())),
-                        protoMethodNameToDescriptorVarExprs.get(m.name())))
-            .collect(Collectors.toList()));
-    secondCtorStatements.addAll(
-        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
-    secondCtorExprs.clear();
-    secondCtorStatements.add(EMPTY_LINE_STATEMENT);
-
-    // Initialize <method>Callable variables.
-    secondCtorExprs.addAll(
-        callableClassMemberVarExprs.entrySet().stream()
-            .map(
-                e ->
-                    createCallableInitExpr(
-                        e.getKey(),
-                        e.getValue(),
-                        callableFactoryVarExpr,
-                        settingsVarExpr,
-                        clientContextVarExpr,
-                        operationsStubClassVarExpr,
-                        thisExpr,
-                        javaStyleMethodNameToTransportSettingsVarExprs))
-            .collect(Collectors.toList()));
-    secondCtorStatements.addAll(
-        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
-    secondCtorExprs.clear();
-    secondCtorStatements.add(EMPTY_LINE_STATEMENT);
-
-    // Instantiate backgroundResources.
-    MethodInvocationExpr getBackgroundResourcesMethodExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(clientContextVarExpr)
-            .setMethodName("getBackgroundResources")
-            .build();
-    VariableExpr backgroundResourcesVarExpr = classMemberVarExprs.get("backgroundResources");
-    secondCtorExprs.add(
-        AssignmentExpr.builder()
-            .setVariableExpr(
-                backgroundResourcesVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
-            .setValueExpr(
-                NewObjectExpr.builder()
-                    .setType(FIXED_TYPESTORE.get("BackgroundResourceAggregation"))
-                    .setArguments(Arrays.asList(getBackgroundResourcesMethodExpr))
-                    .build())
-            .build());
-    secondCtorStatements.addAll(
-        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
-    secondCtorExprs.clear();
+  private MethodDefinition createOperationCallableGetter(Method method, TypeStore typeStore) {
+    return createCallableGetterHelper(method, typeStore, true, false);
+  }
 
-    // Second constructor method.
-    MethodDefinition secondCtor =
-        ctorMakerFn.apply(
-            Arrays.asList(settingsVarExpr, clientContextVarExpr, callableFactoryVarExpr),
-            secondCtorStatements);
+  private MethodDefinition createPagedCallableGetter(Method method, TypeStore typeStore) {
+    return createCallableGetterHelper(method, typeStore, false, true);
+  }
 
-    return Arrays.asList(firstCtor, secondCtor);
+  private MethodDefinition createCallableGetter(Method method, TypeStore typeStore) {
+    return createCallableGetterHelper(method, typeStore, false, false);
   }
 
-  private static Expr createCallableInitExpr(
-      String callableVarName,
-      VariableExpr callableVarExpr,
-      VariableExpr callableFactoryVarExpr,
-      VariableExpr settingsVarExpr,
-      VariableExpr clientContextVarExpr,
-      VariableExpr operationsStubClassVarExpr,
-      Expr thisExpr,
-      Map<String, VariableExpr> javaStyleMethodNameToTransportSettingsVarExprs) {
-    boolean isOperation = callableVarName.endsWith(OPERATION_CALLABLE_NAME);
-    boolean isPaged = callableVarName.endsWith(PAGED_CALLABLE_NAME);
-    int sublength = 0;
-    if (isOperation) {
-      sublength = OPERATION_CALLABLE_NAME.length();
-    } else if (isPaged) {
-      sublength = PAGED_CALLABLE_NAME.length();
-    } else {
-      sublength = CALLABLE_NAME.length();
-    }
-    String javaStyleMethodName = callableVarName.substring(0, callableVarName.length() - sublength);
-    List<Expr> creatorMethodArgVarExprs = null;
-    Expr transportSettingsVarExpr =
-        javaStyleMethodNameToTransportSettingsVarExprs.get(javaStyleMethodName);
-    if (transportSettingsVarExpr == null && isOperation) {
-      // Try again, in case the name dtection above was inaccurate.
-      isOperation = false;
-      sublength = CALLABLE_NAME.length();
-      javaStyleMethodName = callableVarName.substring(0, callableVarName.length() - sublength);
-      transportSettingsVarExpr =
-          javaStyleMethodNameToTransportSettingsVarExprs.get(javaStyleMethodName);
+  private MethodDefinition createCallableGetterHelper(
+      Method method, TypeStore typeStore, boolean isLroCallable, boolean isPaged) {
+    TypeNode returnType;
+    switch (method.stream()) {
+      case CLIENT:
+        returnType = typeStore.get("ClientStreamingCallable");
+        break;
+      case SERVER:
+        returnType = typeStore.get("ServerStreamingCallable");
+        break;
+      case BIDI:
+        returnType = typeStore.get("BidiStreamingCallable");
+        break;
+      case NONE:
+        // Fall through.
+      default:
+        returnType = typeStore.get(isLroCallable ? "OperationCallable" : "UnaryCallable");
     }
-    Preconditions.checkNotNull(
-        transportSettingsVarExpr,
+
+    String methodName =
         String.format(
-            "No transport settings variable found for method name %s", javaStyleMethodName));
-    if (isOperation) {
-      creatorMethodArgVarExprs =
-          Arrays.asList(
-              transportSettingsVarExpr,
-              MethodInvocationExpr.builder()
-                  .setExprReferenceExpr(settingsVarExpr)
-                  .setMethodName(String.format("%sOperationSettings", javaStyleMethodName))
-                  .build(),
-              clientContextVarExpr,
-              operationsStubClassVarExpr);
+            "%s%sCallable",
+            JavaStyle.toLowerCamelCase(method.name()),
+            (isLroCallable ? "Operation" : isPaged ? "Paged" : ""));
+    List<Reference> genericRefs = new ArrayList<>();
+    genericRefs.add(method.inputType().reference());
+    if (method.hasLro() && isLroCallable) {
+      genericRefs.add(method.lro().responseType().reference());
+      genericRefs.add(method.lro().metadataType().reference());
+    } else if (isPaged) {
+      genericRefs.add(
+          typeStore
+              .get(String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, method.name()))
+              .reference());
     } else {
-      creatorMethodArgVarExprs =
-          Arrays.asList(
-              transportSettingsVarExpr,
-              MethodInvocationExpr.builder()
-                  .setExprReferenceExpr(settingsVarExpr)
-                  .setMethodName(String.format("%sSettings", javaStyleMethodName))
-                  .build(),
-              clientContextVarExpr);
+      genericRefs.add(method.outputType().reference());
     }
 
-    String callableCreatorMethodName = getCallableCreatorMethodName(callableVarExpr.type());
-    return AssignmentExpr.builder()
-        .setVariableExpr(callableVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
-        .setValueExpr(
-            MethodInvocationExpr.builder()
-                .setExprReferenceExpr(callableFactoryVarExpr)
-                .setMethodName(callableCreatorMethodName)
-                .setArguments(creatorMethodArgVarExprs)
-                .setReturnType(callableVarExpr.type())
-                .build())
-        .build();
+    List<AnnotationNode> annotations =
+        method.isDeprecated()
+            ? Arrays.asList(AnnotationNode.withType(TypeNode.DEPRECATED))
+            : Collections.emptyList();
+
+    returnType = TypeNode.withReference(returnType.reference().copyAndSetGenerics(genericRefs));
+
+    return createCallableGetterMethodDefinition(returnType, methodName, annotations, typeStore);
   }
 
-  private static String getCallableCreatorMethodName(TypeNode callableVarExprType) {
-    final String typeName = callableVarExprType.reference().name();
-    String streamName = "Unary";
+  private List<MethodDefinition> createOperationsStubGetters(TypeStore typeStore) {
+    List<MethodDefinition> getters = new ArrayList<>();
 
-    // Special handling for pagination methods.
-    if (callableVarExprType.reference().generics().size() == 2
-        && callableVarExprType.reference().generics().get(1).name().endsWith("PagedResponse")) {
-      streamName = "Paged";
-    } else {
-      if (typeName.startsWith("Client")) {
-        streamName = "ClientStreaming";
-      } else if (typeName.startsWith("Server")) {
-        streamName = "ServerStreaming";
-      } else if (typeName.startsWith("Bidi")) {
-        streamName = "BidiStreaming";
-      } else if (typeName.startsWith("Operation")) {
-        streamName = "Operation";
-      }
+    Iterator<String> operationStubNameIt =
+        getTransportContext().transportOperationsStubNames().iterator();
+    Iterator<TypeNode> operationStubTypeIt = getTransportContext().operationsStubTypes().iterator();
+
+    while (operationStubNameIt.hasNext() && operationStubTypeIt.hasNext()) {
+      String methodName =
+          String.format("get%s", JavaStyle.toUpperCamelCase(operationStubNameIt.next()));
+
+      getters.add(
+          createOperationsStubGetterMethodDefinition(
+              operationStubTypeIt.next(), methodName, typeStore));
     }
-    return String.format("create%sCallable", streamName);
-  }
 
-  private static List<MethodDefinition> createCallableGetterMethods(
-      Map<String, VariableExpr> callableClassMemberVarExprs) {
-    return callableClassMemberVarExprs.entrySet().stream()
-        .map(
-            e ->
-                MethodDefinition.builder()
-                    .setIsOverride(true)
-                    .setScope(ScopeNode.PUBLIC)
-                    .setReturnType(e.getValue().type())
-                    .setName(e.getKey())
-                    .setReturnExpr(e.getValue())
-                    .build())
-        .collect(Collectors.toList());
+    return getters;
   }
 
-  private List<MethodDefinition> createStubOverrideMethods(
-      VariableExpr backgroundResourcesVarExpr) {
-    Function<String, MethodDefinition.Builder> methodMakerStarterFn =
-        methodName ->
-            MethodDefinition.builder()
-                .setIsOverride(true)
-                .setScope(ScopeNode.PUBLIC)
-                .setName(methodName);
-
-    Function<String, MethodDefinition> voidMethodMakerFn =
-        methodName ->
-            methodMakerStarterFn
-                .apply(methodName)
-                .setReturnType(TypeNode.VOID)
-                .setBody(
-                    Arrays.asList(
-                        ExprStatement.withExpr(
-                            MethodInvocationExpr.builder()
-                                .setExprReferenceExpr(backgroundResourcesVarExpr)
-                                .setMethodName(methodName)
-                                .build())))
-                .build();
-
-    Function<String, MethodDefinition> booleanMethodMakerFn =
-        methodName ->
-            methodMakerStarterFn
-                .apply(methodName)
-                .setReturnType(TypeNode.BOOLEAN)
-                .setReturnExpr(
-                    MethodInvocationExpr.builder()
-                        .setExprReferenceExpr(backgroundResourcesVarExpr)
-                        .setMethodName(methodName)
-                        .setReturnType(TypeNode.BOOLEAN)
-                        .build())
-                .build();
-
-    List<MethodDefinition> javaMethods = new ArrayList<>();
-    javaMethods.add(
-        methodMakerStarterFn
-            .apply("close")
-            .setIsFinal(true)
+  private static List<MethodDefinition> createBackgroundResourceMethodOverrides() {
+    MethodDefinition closeMethod =
+        MethodDefinition.builder()
+            .setIsOverride(true)
+            .setScope(ScopeNode.PUBLIC)
+            .setIsAbstract(true)
             .setReturnType(TypeNode.VOID)
-            .setBody(
-                Arrays.asList(
-                    ExprStatement.withExpr(
-                        MethodInvocationExpr.builder().setMethodName("shutdown").build())))
-            .build());
-    javaMethods.add(voidMethodMakerFn.apply("shutdown"));
-    javaMethods.add(booleanMethodMakerFn.apply("isShutdown"));
-    javaMethods.add(booleanMethodMakerFn.apply("isTerminated"));
-    javaMethods.add(voidMethodMakerFn.apply("shutdownNow"));
-
-    List<VariableExpr> awaitTerminationArgs =
-        Arrays.asList(
-            VariableExpr.withVariable(
-                Variable.builder().setName("duration").setType(TypeNode.LONG).build()),
-            VariableExpr.withVariable(
-                Variable.builder()
-                    .setName("unit")
-                    .setType(FIXED_TYPESTORE.get("TimeUnit"))
-                    .build()));
-    javaMethods.add(
-        methodMakerStarterFn
-            .apply("awaitTermination")
-            .setReturnType(TypeNode.BOOLEAN)
-            .setArguments(
-                awaitTerminationArgs.stream()
-                    .map(v -> v.toBuilder().setIsDecl(true).build())
-                    .collect(Collectors.toList()))
-            .setThrowsExceptions(Arrays.asList(FIXED_TYPESTORE.get("InterruptedException")))
-            .setReturnExpr(
-                MethodInvocationExpr.builder()
-                    .setExprReferenceExpr(backgroundResourcesVarExpr)
-                    .setMethodName("awaitTermination")
-                    .setArguments(
-                        awaitTerminationArgs.stream()
-                            .map(v -> (Expr) v)
-                            .collect(Collectors.toList()))
-                    .setReturnType(TypeNode.BOOLEAN)
-                    .build())
-            .build());
-    return javaMethods;
+            .setName("close")
+            .build();
+    return Arrays.asList(closeMethod);
   }
 
-  private TypeStore createDynamicTypes(Service service, String stubPakkage) {
-    TypeStore typeStore = new TypeStore();
-    typeStore.putAll(
-        stubPakkage,
+  private static TypeStore createTypes(Service service, Map<String, Message> messageTypes) {
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
-            getTransportContext().classNames().getTransportServiceStubClassName(service),
-            getTransportContext().classNames().getServiceStubSettingsClassName(service),
-            getTransportContext().classNames().getServiceStubClassName(service),
-            getTransportContext().classNames().getTransportServiceCallableFactoryClassName(service)));
+            BackgroundResource.class,
+            BetaApi.class,
+            BidiStreamingCallable.class,
+            ClientStreamingCallable.class,
+            Generated.class,
+            Operation.class,
+            OperationCallable.class,
+            ServerStreamingCallable.class,
+            UnaryCallable.class,
+            UnsupportedOperationException.class);
+    TypeStore typeStore = new TypeStore(concreteClazzes);
+
+    typeStore.put("com.google.longrunning.stub", "OperationsStub");
+
     // Pagination types.
     typeStore.putAll(
         service.pakkage(),
@@ -852,52 +254,44 @@ private TypeStore createDynamicTypes(Service service, String stubPakkage) {
             .map(m -> String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, m.name()))
             .collect(Collectors.toList()),
         true,
-        getTransportContext().classNames().getServiceClientClassName(service));
-    return typeStore;
-  }
+        ClassNames.getServiceClientClassName(service));
 
-  private static TypeNode getCallableType(Method protoMethod) {
-    TypeNode callableType = FIXED_TYPESTORE.get("UnaryCallable");
-    switch (protoMethod.stream()) {
-      case CLIENT:
-        callableType = FIXED_TYPESTORE.get("ClientStreamingCallable");
-        break;
-      case SERVER:
-        callableType = FIXED_TYPESTORE.get("ServerStreamingCallable");
-        break;
-      case BIDI:
-        callableType = FIXED_TYPESTORE.get("BidiStreamingCallable");
-        break;
-      case NONE:
-        // Fall through
-      default:
-        // Fall through
-    }
-
-    return TypeNode.withReference(
-        callableType
-            .reference()
-            .copyAndSetGenerics(
-                Arrays.asList(
-                    protoMethod.inputType().reference(), protoMethod.outputType().reference())));
+    return typeStore;
   }
 
-  private CommentStatement createProtectedCtorComment(Service service) {
-    return CommentStatement.withComment(
-        JavaDocComment.withComment(
-            String.format(
-                "Constructs an instance of %s, using the given settings. This is protected so that"
-                    + " it is easy to make a subclass, but otherwise, the static factory methods"
-                    + " should be  preferred.",
-                getTransportContext().classNames().getTransportServiceStubClassName(service))));
+  protected MethodDefinition createCallableGetterMethodDefinition(
+      TypeNode returnType,
+      String methodName,
+      List<AnnotationNode> annotations,
+      TypeStore typeStore) {
+    return MethodDefinition.builder()
+        .setScope(ScopeNode.PUBLIC)
+        .setAnnotations(annotations)
+        .setName(methodName)
+        .setReturnType(returnType)
+        .setBody(
+            Arrays.asList(
+                ExprStatement.withExpr(
+                    ThrowExpr.builder()
+                        .setType(typeStore.get("UnsupportedOperationException"))
+                        .setMessageExpr(String.format("Not implemented: %s()", methodName))
+                        .build())))
+        .build();
   }
 
-  protected String getProtoRpcFullMethodName(Service protoService, Method protoMethod) {
-    if (protoMethod.isMixin()) {
-      return String.format("%s/%s", protoMethod.mixedInApiName(), protoMethod.name());
-    }
-
-    return String.format(
-        "%s.%s/%s", protoService.protoPakkage(), protoService.name(), protoMethod.name());
+  protected MethodDefinition createOperationsStubGetterMethodDefinition(
+      TypeNode returnType, String methodName, TypeStore typeStore) {
+    return MethodDefinition.builder()
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(returnType)
+        .setName(methodName)
+        .setBody(
+            Arrays.asList(
+                ExprStatement.withExpr(
+                    ThrowExpr.builder()
+                        .setType(typeStore.get("UnsupportedOperationException"))
+                        .setMessageExpr(String.format("Not implemented: %s()", methodName))
+                        .build())))
+        .build();
   }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java
index fb2d350011..7a38adba80 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceStubSettingsClassComposer.java
@@ -61,6 +61,7 @@
 import com.google.api.generator.engine.ast.MethodDefinition;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
 import com.google.api.generator.engine.ast.NewObjectExpr;
+import com.google.api.generator.engine.ast.PrimitiveValue;
 import com.google.api.generator.engine.ast.Reference;
 import com.google.api.generator.engine.ast.ReferenceConstructorExpr;
 import com.google.api.generator.engine.ast.RelationalOperationExpr;
@@ -104,6 +105,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -138,8 +140,6 @@ public abstract class AbstractServiceStubSettingsClassComposer implements ClassC
 
   protected static final TypeStore FIXED_TYPESTORE = createStaticTypes();
 
-  private static final VariableExpr DEFAULT_SERVICE_SCOPES_VAR_EXPR =
-      createDefaultServiceScopesVarExpr();
   private static final VariableExpr NESTED_UNARY_METHOD_SETTINGS_BUILDERS_VAR_EXPR =
       createNestedUnaryMethodSettingsBuildersVarExpr();
   private static final VariableExpr NESTED_RETRYABLE_CODE_DEFINITIONS_VAR_EXPR =
@@ -149,6 +149,9 @@ public abstract class AbstractServiceStubSettingsClassComposer implements ClassC
 
   private final TransportContext transportContext;
 
+  protected static final VariableExpr DEFAULT_SERVICE_SCOPES_VAR_EXPR =
+      createDefaultServiceScopesVarExpr();
+
   protected AbstractServiceStubSettingsClassComposer(TransportContext transportContext) {
     this.transportContext = transportContext;
   }
@@ -196,11 +199,152 @@ public GapicClass generate(GapicContext context, Service service) {
     return GapicClass.create(GapicClass.Kind.STUB, classDef);
   }
 
-  protected abstract MethodDefinition createDefaultTransportTransportProviderBuilderMethod();
+  protected MethodDefinition createDefaultCredentialsProviderBuilderMethod() {
+    TypeNode returnType =
+        TypeNode.withReference(
+            ConcreteReference.withClazz(GoogleCredentialsProvider.Builder.class));
+    MethodInvocationExpr credsProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(FIXED_TYPESTORE.get("GoogleCredentialsProvider"))
+            .setMethodName("newBuilder")
+            .build();
+    credsProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(credsProviderBuilderExpr)
+            .setMethodName("setScopesToApply")
+            .setArguments(DEFAULT_SERVICE_SCOPES_VAR_EXPR)
+            .setReturnType(returnType)
+            .build();
+    return MethodDefinition.builder()
+        .setHeaderCommentStatements(
+            SettingsCommentComposer.DEFAULT_CREDENTIALS_PROVIDER_BUILDER_METHOD_COMMENT)
+        .setScope(ScopeNode.PUBLIC)
+        .setIsStatic(true)
+        .setReturnType(returnType)
+        .setName("defaultCredentialsProviderBuilder")
+        .setReturnExpr(credsProviderBuilderExpr)
+        .build();
+  }
+
+  protected List<MethodDefinition> createDefaultTransportTransportProviderBuilderMethods() {
+    // Create the defaultGrpcTransportProviderBuilder method.
+    Iterator<Class<?>> providerClassIt =
+        getTransportContext().instantiatingChannelProviderClasses().iterator();
+    Iterator<Class<?>> providerBuilderClassIt =
+        getTransportContext().instantiatingChannelProviderBuilderClasses().iterator();
+    Iterator<String> builderNamesIt =
+        getTransportContext().defaultTransportProviderBuilderNames().iterator();
+
+    List<MethodDefinition> methods = new ArrayList<>();
+
+    while (providerClassIt.hasNext()
+        && providerBuilderClassIt.hasNext()
+        && builderNamesIt.hasNext()) {
+      TypeNode returnType =
+          TypeNode.withReference(ConcreteReference.withClazz(providerBuilderClassIt.next()));
+      TypeNode channelProviderType =
+          TypeNode.withReference(ConcreteReference.withClazz(providerClassIt.next()));
+
+      MethodInvocationExpr transportChannelProviderBuilderExpr =
+          MethodInvocationExpr.builder()
+              .setStaticReferenceType(channelProviderType)
+              .setMethodName("newBuilder")
+              .setReturnType(returnType)
+              .build();
+      Expr returnExpr =
+          initializeTransportProviderBuilder(transportChannelProviderBuilderExpr, returnType);
+
+      MethodDefinition method =
+          MethodDefinition.builder()
+              .setHeaderCommentStatements(
+                  SettingsCommentComposer.DEFAULT_TRANSPORT_PROVIDER_BUILDER_METHOD_COMMENT)
+              .setScope(ScopeNode.PUBLIC)
+              .setIsStatic(true)
+              .setReturnType(returnType)
+              .setName(builderNamesIt.next())
+              .setReturnExpr(returnExpr)
+              .build();
+      methods.add(method);
+    }
+
+    return methods;
+  }
+
+  protected Expr initializeTransportProviderBuilder(
+      MethodInvocationExpr transportChannelProviderBuilderExpr, TypeNode returnType) {
+    return transportChannelProviderBuilderExpr;
+  }
 
-  protected abstract MethodDefinition createDefaultApiClientHeaderProviderBuilderMethod(
+  protected abstract List<MethodDefinition> createApiClientHeaderProviderBuilderMethods(
       Service service, TypeStore typeStore);
 
+  protected MethodDefinition createApiClientHeaderProviderBuilderMethod(
+      Service service,
+      TypeStore typeStore,
+      String methodName,
+      TypeNode gaxPropertiesType,
+      String getTokenMethodName,
+      String getVersionMethodName) {
+    TypeNode returnType =
+        TypeNode.withReference(ConcreteReference.withClazz(ApiClientHeaderProvider.Builder.class));
+    MethodInvocationExpr returnExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(FIXED_TYPESTORE.get("ApiClientHeaderProvider"))
+            .setMethodName("newBuilder")
+            .build();
+
+    MethodInvocationExpr versionArgExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(FIXED_TYPESTORE.get("GaxProperties"))
+            .setMethodName("getLibraryVersion")
+            .setArguments(
+                VariableExpr.builder()
+                    .setVariable(
+                        Variable.builder().setType(TypeNode.CLASS_OBJECT).setName("class").build())
+                    .setStaticReferenceType(
+                        typeStore.get(ClassNames.getServiceStubSettingsClassName(service)))
+                    .build())
+            .build();
+
+    returnExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(returnExpr)
+            .setMethodName("setGeneratedLibToken")
+            .setArguments(ValueExpr.withValue(StringObjectValue.withValue("gapic")), versionArgExpr)
+            .build();
+    returnExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(returnExpr)
+            .setMethodName("setTransportToken")
+            .setArguments(
+                MethodInvocationExpr.builder()
+                    .setStaticReferenceType(gaxPropertiesType)
+                    .setMethodName(getTokenMethodName)
+                    .build(),
+                MethodInvocationExpr.builder()
+                    .setStaticReferenceType(gaxPropertiesType)
+                    .setMethodName(getVersionMethodName)
+                    .build())
+            .setReturnType(returnType)
+            .build();
+
+    AnnotationNode annotation =
+        AnnotationNode.builder()
+            .setType(FIXED_TYPESTORE.get("BetaApi"))
+            .setDescription(
+                "The surface for customizing headers is not stable yet and may change in the"
+                    + " future.")
+            .build();
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(annotation))
+        .setScope(ScopeNode.PUBLIC)
+        .setIsStatic(true)
+        .setReturnType(returnType)
+        .setName(methodName)
+        .setReturnExpr(returnExpr)
+        .build();
+  }
+
   public abstract MethodDefinition createDefaultTransportChannelProviderMethod();
 
   private List<AnnotationNode> createClassAnnotations(Service service) {
@@ -305,8 +449,7 @@ private static List<Statement> createClassStatements(
     // Assign DEFAULT_SERVICE_SCOPES.
     statements.add(SettingsCommentComposer.DEFAULT_SCOPES_COMMENT);
     VariableExpr defaultServiceScopesDeclVarExpr =
-        DEFAULT_SERVICE_SCOPES_VAR_EXPR
-            .toBuilder()
+        DEFAULT_SERVICE_SCOPES_VAR_EXPR.toBuilder()
             .setIsDecl(true)
             .setScope(ScopeNode.PRIVATE)
             .setIsStatic(true)
@@ -402,7 +545,7 @@ private static List<Expr> createPagingStaticAssignExprs(
               "No method found for message type %s for method %s among %s",
               pagedResponseMessageKey, method.name(), messageTypes.keySet()));
 
-      Field repeatedPagedResultsField = pagedResponseMessage.findAndUnwrapFirstRepeatedField();
+      Field repeatedPagedResultsField = pagedResponseMessage.findAndUnwrapPaginatedRepeatedField();
       Preconditions.checkNotNull(
           repeatedPagedResultsField,
           String.format(
@@ -511,7 +654,7 @@ private static Expr createPagedListDescriptorAssignExpr(
     returnExpr =
         MethodInvocationExpr.builder()
             .setExprReferenceExpr(newBuilderExpr)
-            .setMethodName("setPageSize")
+            .setMethodName("set" + JavaStyle.toUpperCamelCase(method.pageSizeFieldName()))
             .setArguments(pageSizeVarExpr)
             .build();
     returnExpr =
@@ -542,7 +685,7 @@ private static Expr createPagedListDescriptorAssignExpr(
             .setReturnExpr(
                 MethodInvocationExpr.builder()
                     .setExprReferenceExpr(payloadVarExpr)
-                    .setMethodName("getPageSize")
+                    .setMethodName("get" + JavaStyle.toUpperCamelCase(method.pageSizeFieldName()))
                     .setReturnType(returnType)
                     .build())
             .build());
@@ -572,29 +715,71 @@ private static Expr createPagedListDescriptorAssignExpr(
                 .setClazz(Iterable.class)
                 .setGenerics(Arrays.asList(repeatedResponseType.reference()))
                 .build());
-    Expr getResponsesListExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(payloadVarExpr)
-            .setMethodName(
-                String.format("get%sList", JavaStyle.toUpperCamelCase(repeatedFieldName)))
-            .setReturnType(returnType)
-            .build();
+
+    Expr getResponsesExpr;
+    Expr elseExpr;
+    Expr thenExpr;
+    if (repeatedResponseType.reference() != null
+        && "java.util.Map.Entry".equals(repeatedResponseType.reference().fullName())) {
+      getResponsesExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(payloadVarExpr)
+              .setMethodName(
+                  String.format("get%sMap", JavaStyle.toUpperCamelCase(repeatedFieldName)))
+              .setReturnType(returnType)
+              .build();
+      thenExpr =
+          MethodInvocationExpr.builder()
+              .setStaticReferenceType(
+                  TypeNode.withReference(ConcreteReference.withClazz(Collections.class)))
+              .setGenerics(Arrays.asList(repeatedResponseType.reference()))
+              .setMethodName("emptySet")
+              .setReturnType(returnType)
+              .build();
+      elseExpr =
+          MethodInvocationExpr.builder()
+              .setMethodName("entrySet")
+              .setExprReferenceExpr(
+                  MethodInvocationExpr.builder()
+                      .setExprReferenceExpr(payloadVarExpr)
+                      .setMethodName(
+                          String.format("get%sMap", JavaStyle.toUpperCamelCase(repeatedFieldName)))
+                      .build())
+              .setReturnType(returnType)
+              .build();
+    } else {
+      getResponsesExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(payloadVarExpr)
+              .setMethodName(
+                  String.format("get%sList", JavaStyle.toUpperCamelCase(repeatedFieldName)))
+              .setReturnType(returnType)
+              .build();
+      thenExpr =
+          MethodInvocationExpr.builder()
+              .setStaticReferenceType(
+                  TypeNode.withReference(ConcreteReference.withClazz(ImmutableList.class)))
+              .setGenerics(Arrays.asList(repeatedResponseType.reference()))
+              .setMethodName("of")
+              .setReturnType(returnType)
+              .build();
+      elseExpr = getResponsesExpr;
+    }
+    // While protobufs should not be null, this null-check is needed to protect against NPEs
+    // in paged iteration on clients that use legacy HTTP/JSON types, as these clients can
+    // actually return null instead of an empty list.
+    // Context:
+    //   Original issue: https://github.com/googleapis/google-cloud-java/issues/3736
+    //   Relevant discussion where this check was first added:
+    //        https://github.com/googleapis/google-cloud-java/pull/4499#discussion_r257057409
     Expr conditionExpr =
-        RelationalOperationExpr.equalToWithExprs(getResponsesListExpr, ValueExpr.createNullExpr());
-    Expr thenExpr =
-        MethodInvocationExpr.builder()
-            .setStaticReferenceType(
-                TypeNode.withReference(ConcreteReference.withClazz(ImmutableList.class)))
-            .setGenerics(Arrays.asList(repeatedResponseType.reference()))
-            .setMethodName("of")
-            .setReturnType(returnType)
-            .build();
+        RelationalOperationExpr.equalToWithExprs(getResponsesExpr, ValueExpr.createNullExpr());
 
     returnExpr =
         TernaryExpr.builder()
             .setConditionExpr(conditionExpr)
             .setThenExpr(thenExpr)
-            .setElseExpr(getResponsesListExpr)
+            .setElseExpr(elseExpr)
             .build();
     anonClassMethods.add(
         methodStarterBuilder
@@ -614,8 +799,7 @@ private static Expr createPagedListDescriptorAssignExpr(
     // Declare and assign the variable.
     return AssignmentExpr.builder()
         .setVariableExpr(
-            pagedListDescVarExpr
-                .toBuilder()
+            pagedListDescVarExpr.toBuilder()
                 .setIsDecl(true)
                 .setScope(ScopeNode.PRIVATE)
                 .setIsStatic(true)
@@ -754,8 +938,7 @@ private static Expr createPagedListResponseFactoryAssignExpr(
 
     return AssignmentExpr.builder()
         .setVariableExpr(
-            pagedListResponseFactoryVarExpr
-                .toBuilder()
+            pagedListResponseFactoryVarExpr.toBuilder()
                 .setIsDecl(true)
                 .setScope(ScopeNode.PRIVATE)
                 .setIsStatic(true)
@@ -775,6 +958,7 @@ private List<MethodDefinition> createClassMethods(
         createMethodSettingsGetterMethods(methodSettingsMemberVarExprs, deprecatedSettingVarNames));
     javaMethods.add(createCreateStubMethod(service, typeStore));
     javaMethods.addAll(createDefaultHelperAndGetterMethods(service, typeStore));
+    javaMethods.addAll(createNewBuilderMethods(service, typeStore, "newBuilder", "createDefault"));
     javaMethods.addAll(createBuilderHelperMethods(service, typeStore));
     javaMethods.add(createClassConstructor(service, methodSettingsMemberVarExprs, typeStore));
     return javaMethods;
@@ -807,12 +991,7 @@ private static List<MethodDefinition> createMethodSettingsGetterMethods(
 
   private MethodDefinition createCreateStubMethod(Service service, TypeStore typeStore) {
     // Set up the if-statement.
-    Expr tRansportNameExpr =
-        MethodInvocationExpr.builder()
-            .setStaticReferenceType(
-                getTransportContext().transportChannelType())
-            .setMethodName(getTransportContext().transportGetterName())
-            .build();
+    List<Statement> bodyStatements = new ArrayList<>();
 
     Expr getTransportNameExpr =
         MethodInvocationExpr.builder().setMethodName("getTransportChannelProvider").build();
@@ -822,30 +1001,48 @@ private MethodDefinition createCreateStubMethod(Service service, TypeStore typeS
             .setMethodName("getTransportName")
             .build();
 
-    Expr ifConditionExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(getTransportNameExpr)
-            .setMethodName("equals")
-            .setArguments(tRansportNameExpr)
-            .setReturnType(TypeNode.BOOLEAN)
-            .build();
+    Iterator<TypeNode> channelTypesIt = getTransportContext().transportChannelTypes().iterator();
+    Iterator<String> getterNameIt = getTransportContext().transportGetterNames().iterator();
+    Iterator<String> serivceStubClassNameIt =
+        getTransportContext().classNames().getTransportServiceStubClassNames(service).iterator();
 
-    Expr createExpr =
-        MethodInvocationExpr.builder()
-            .setStaticReferenceType(
-                typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service)))
-            .setMethodName("create")
-            .setArguments(
-                ValueExpr.withValue(
-                    ThisObjectValue.withType(
-                        typeStore.get(ClassNames.getServiceStubSettingsClassName(service)))))
-            .build();
+    while (channelTypesIt.hasNext() && getterNameIt.hasNext()) {
+      TypeNode channelType = channelTypesIt.next();
+      String getterName = getterNameIt.next();
+      String serivceStubClassName = serivceStubClassNameIt.next();
 
-    IfStatement ifStatement =
-        IfStatement.builder()
-            .setConditionExpr(ifConditionExpr)
-            .setBody(Arrays.asList(ExprStatement.withExpr(ReturnExpr.withExpr(createExpr))))
-            .build();
+      Expr tRansportNameExpr =
+          MethodInvocationExpr.builder()
+              .setStaticReferenceType(channelType)
+              .setMethodName(getterName)
+              .build();
+
+      Expr ifConditionExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(getTransportNameExpr)
+              .setMethodName("equals")
+              .setArguments(tRansportNameExpr)
+              .setReturnType(TypeNode.BOOLEAN)
+              .build();
+
+      Expr createExpr =
+          MethodInvocationExpr.builder()
+              .setStaticReferenceType(typeStore.get(serivceStubClassName))
+              .setMethodName("create")
+              .setArguments(
+                  ValueExpr.withValue(
+                      ThisObjectValue.withType(
+                          typeStore.get(ClassNames.getServiceStubSettingsClassName(service)))))
+              .build();
+
+      IfStatement ifStatement =
+          IfStatement.builder()
+              .setConditionExpr(ifConditionExpr)
+              .setBody(Arrays.asList(ExprStatement.withExpr(ReturnExpr.withExpr(createExpr))))
+              .build();
+
+      bodyStatements.add(ifStatement);
+    }
 
     // Set up exception throwing.
     Expr errorMessageExpr =
@@ -862,6 +1059,8 @@ private MethodDefinition createCreateStubMethod(Service service, TypeStore typeS
         ExprStatement.withExpr(
             ThrowExpr.builder().setType(exceptionType).setMessageExpr(errorMessageExpr).build());
 
+    bodyStatements.add(throwStatement);
+
     // Put the method together.
     TypeNode returnType = typeStore.get(ClassNames.getServiceStubClassName(service));
     AnnotationNode annotation =
@@ -877,7 +1076,7 @@ private MethodDefinition createCreateStubMethod(Service service, TypeStore typeS
         .setReturnType(returnType)
         .setName("createStub")
         .setThrowsExceptions(Arrays.asList(TypeNode.withExceptionClazz(IOException.class)))
-        .setBody(Arrays.asList(ifStatement, throwStatement))
+        .setBody(bodyStatements)
         .build();
   }
 
@@ -918,77 +1117,75 @@ private List<MethodDefinition> createDefaultHelperAndGetterMethods(
             .setReturnExpr(ValueExpr.withValue(StringObjectValue.withValue(service.defaultHost())))
             .build());
 
-    // Create the getDefaultServiceScopes method.
-    returnType =
-        TypeNode.withReference(
-            ConcreteReference.builder()
-                .setClazz(List.class)
-                .setGenerics(Arrays.asList(TypeNode.STRING.reference()))
-                .build());
+    // Create the getDefaultMtlsEndpoint method.
+    returnType = TypeNode.STRING;
     javaMethods.add(
         MethodDefinition.builder()
             .setHeaderCommentStatements(
-                SettingsCommentComposer.DEFAULT_SERVICE_SCOPES_METHOD_COMMENT)
+                SettingsCommentComposer.DEFAULT_SERVICE_MTLS_ENDPOINT_METHOD_COMMENT)
             .setScope(ScopeNode.PUBLIC)
             .setIsStatic(true)
             .setReturnType(returnType)
-            .setName("getDefaultServiceScopes")
-            .setReturnExpr(DEFAULT_SERVICE_SCOPES_VAR_EXPR)
+            .setName("getDefaultMtlsEndpoint")
+            .setReturnExpr(
+                ValueExpr.withValue(
+                    StringObjectValue.withValue(
+                        service.defaultHost().replace(".googleapis.com", ".mtls.googleapis.com"))))
             .build());
 
-    // Create the defaultCredentialsProviderBuilder method.
+    // Create the getDefaultServiceScopes method.
     returnType =
         TypeNode.withReference(
-            ConcreteReference.withClazz(GoogleCredentialsProvider.Builder.class));
-    MethodInvocationExpr credsProviderBuilderExpr =
-        MethodInvocationExpr.builder()
-            .setStaticReferenceType(FIXED_TYPESTORE.get("GoogleCredentialsProvider"))
-            .setMethodName("newBuilder")
-            .build();
-    credsProviderBuilderExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(credsProviderBuilderExpr)
-            .setMethodName("setScopesToApply")
-            .setArguments(DEFAULT_SERVICE_SCOPES_VAR_EXPR)
-            .setReturnType(returnType)
-            .build();
+            ConcreteReference.builder()
+                .setClazz(List.class)
+                .setGenerics(Arrays.asList(TypeNode.STRING.reference()))
+                .build());
     javaMethods.add(
         MethodDefinition.builder()
             .setHeaderCommentStatements(
-                SettingsCommentComposer.DEFAULT_CREDENTIALS_PROVIDER_BUILDER_METHOD_COMMENT)
+                SettingsCommentComposer.DEFAULT_SERVICE_SCOPES_METHOD_COMMENT)
             .setScope(ScopeNode.PUBLIC)
             .setIsStatic(true)
             .setReturnType(returnType)
-            .setName("defaultCredentialsProviderBuilder")
-            .setReturnExpr(credsProviderBuilderExpr)
+            .setName("getDefaultServiceScopes")
+            .setReturnExpr(DEFAULT_SERVICE_SCOPES_VAR_EXPR)
             .build());
 
-    javaMethods.add(createDefaultTransportTransportProviderBuilderMethod());
+    javaMethods.add(createDefaultCredentialsProviderBuilderMethod());
+    javaMethods.addAll(createDefaultTransportTransportProviderBuilderMethods());
     javaMethods.add(createDefaultTransportChannelProviderMethod());
-    javaMethods.add(createDefaultApiClientHeaderProviderBuilderMethod(service, typeStore));
+    javaMethods.addAll(createApiClientHeaderProviderBuilderMethods(service, typeStore));
 
     return javaMethods;
   }
 
-  private static List<MethodDefinition> createBuilderHelperMethods(Service service, TypeStore typeStore) {
-    List<MethodDefinition> javaMethods = new ArrayList<>();
+  protected List<MethodDefinition> createNewBuilderMethods(
+      Service service,
+      TypeStore typeStore,
+      String newBuilderMethodName,
+      String createDefaultMethodName) {
     // Create the newBuilder() method.
     final TypeNode builderReturnType = typeStore.get(NESTED_BUILDER_CLASS_NAME);
-    javaMethods.add(
+    return ImmutableList.of(
         MethodDefinition.builder()
             .setHeaderCommentStatements(SettingsCommentComposer.NEW_BUILDER_METHOD_COMMENT)
             .setScope(ScopeNode.PUBLIC)
             .setIsStatic(true)
             .setReturnType(builderReturnType)
-            .setName("newBuilder")
+            .setName(newBuilderMethodName)
             .setReturnExpr(
                 MethodInvocationExpr.builder()
                     .setStaticReferenceType(builderReturnType)
-                    .setMethodName("createDefault")
+                    .setMethodName(createDefaultMethodName)
                     .setReturnType(builderReturnType)
                     .build())
             .build());
+  }
 
+  protected List<MethodDefinition> createBuilderHelperMethods(
+      Service service, TypeStore typeStore) {
+    List<MethodDefinition> javaMethods = new ArrayList<>();
+    final TypeNode builderReturnType = typeStore.get(NESTED_BUILDER_CLASS_NAME);
     // Create the newBuilder(ClientContext) method.
     Function<Expr, NewObjectExpr> newBuilderFn =
         argExpr -> NewObjectExpr.builder().setType(builderReturnType).setArguments(argExpr).build();
@@ -1077,11 +1274,10 @@ private static MethodDefinition createClassConstructor(
         .build();
   }
 
-  private static ClassDefinition createNestedBuilderClass(
+  private ClassDefinition createNestedBuilderClass(
       Service service, @Nullable GapicServiceConfig serviceConfig, TypeStore typeStore) {
     // TODO(miraleung): Robustify this against a null serviceConfig.
     String thisClassName = ClassNames.getServiceStubSettingsClassName(service);
-    TypeNode outerThisClassType = typeStore.get(thisClassName);
 
     String className = "Builder";
 
@@ -1177,7 +1373,7 @@ private static List<Statement> createNestedClassStatements(
     return statements;
   }
 
-  private static List<MethodDefinition> createNestedClassMethods(
+  private List<MethodDefinition> createNestedClassMethods(
       Service service,
       GapicServiceConfig serviceConfig,
       TypeNode superType,
@@ -1188,7 +1384,7 @@ private static List<MethodDefinition> createNestedClassMethods(
     nestedClassMethods.addAll(
         createNestedClassConstructorMethods(
             service, serviceConfig, nestedMethodSettingsMemberVarExprs, typeStore));
-    nestedClassMethods.add(createNestedClassCreateDefaultMethod(typeStore));
+    nestedClassMethods.addAll(createNestedClassCreateDefaultMethods(typeStore));
     nestedClassMethods.add(createNestedClassInitDefaultsMethod(service, serviceConfig, typeStore));
     nestedClassMethods.add(createNestedClassApplyToAllUnaryMethodsMethod(superType, typeStore));
     nestedClassMethods.add(createNestedClassUnaryMethodSettingsBuilderGetterMethod());
@@ -1199,7 +1395,7 @@ private static List<MethodDefinition> createNestedClassMethods(
     return nestedClassMethods;
   }
 
-  private static MethodDefinition createNestedClassInitDefaultsMethod(
+  private MethodDefinition createNestedClassInitDefaultsMethod(
       Service service, @Nullable GapicServiceConfig serviceConfig, TypeStore typeStore) {
     // TODO(miraleung): Robustify this against a null serviceConfig.
     TypeNode builderType = typeStore.get(NESTED_BUILDER_CLASS_NAME);
@@ -1254,7 +1450,9 @@ private static MethodDefinition createNestedClassInitDefaultsMethod(
                   method,
                   builderVarExpr,
                   NESTED_RETRYABLE_CODE_DEFINITIONS_VAR_EXPR,
-                  NESTED_RETRY_PARAM_DEFINITIONS_VAR_EXPR)));
+                  NESTED_RETRY_PARAM_DEFINITIONS_VAR_EXPR,
+                  getTransportContext().operationResponseTransformerType(),
+                  getTransportContext().operationMetadataTransformerType())));
       bodyStatements.add(EMPTY_LINE_STATEMENT);
     }
 
@@ -1524,7 +1722,22 @@ private static List<MethodDefinition> createNestedClassConstructorMethods(
     return ctorMethods;
   }
 
-  private static MethodDefinition createNestedClassCreateDefaultMethod(TypeStore typeStore) {
+  protected List<MethodDefinition> createNestedClassCreateDefaultMethods(TypeStore typeStore) {
+    return Collections.singletonList(
+        createNestedClassCreateDefaultMethod(
+            typeStore,
+            "createDefault",
+            "defaultTransportChannelProvider",
+            null,
+            "defaultApiClientHeaderProviderBuilder"));
+  }
+
+  protected MethodDefinition createNestedClassCreateDefaultMethod(
+      TypeStore typeStore,
+      String methodName,
+      String defaultTransportChannelProvider,
+      String defaultTransportChannelProviderBuilder,
+      String defaultApiClientHeaderProviderBuilder) {
     List<Statement> bodyStatements = new ArrayList<>();
 
     // Initialize the builder: Builder builder = new Builder((ClientContext) null);
@@ -1549,15 +1762,32 @@ private static MethodDefinition createNestedClassCreateDefaultMethod(TypeStore t
     bodyStatements.add(EMPTY_LINE_STATEMENT);
 
     List<Expr> bodyExprs = new ArrayList<>();
-    bodyExprs.add(
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(builderVarExpr)
-            .setMethodName("setTransportChannelProvider")
-            .setArguments(
-                MethodInvocationExpr.builder()
-                    .setMethodName("defaultTransportChannelProvider")
-                    .build())
-            .build());
+
+    if (defaultTransportChannelProvider != null) {
+      bodyExprs.add(
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(builderVarExpr)
+              .setMethodName("setTransportChannelProvider")
+              .setArguments(
+                  MethodInvocationExpr.builder()
+                      .setMethodName(defaultTransportChannelProvider)
+                      .build())
+              .build());
+    } else {
+      bodyExprs.add(
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(builderVarExpr)
+              .setMethodName("setTransportChannelProvider")
+              .setArguments(
+                  MethodInvocationExpr.builder()
+                      .setExprReferenceExpr(
+                          MethodInvocationExpr.builder()
+                              .setMethodName(defaultTransportChannelProviderBuilder)
+                              .build())
+                      .setMethodName("build")
+                      .build())
+              .build());
+    }
 
     bodyExprs.add(
         MethodInvocationExpr.builder()
@@ -1581,7 +1811,7 @@ private static MethodDefinition createNestedClassCreateDefaultMethod(TypeStore t
                 MethodInvocationExpr.builder()
                     .setExprReferenceExpr(
                         MethodInvocationExpr.builder()
-                            .setMethodName("defaultApiClientHeaderProviderBuilder")
+                            .setMethodName(defaultApiClientHeaderProviderBuilder)
                             .build())
                     .setMethodName("build")
                     .build())
@@ -1594,6 +1824,21 @@ private static MethodDefinition createNestedClassCreateDefaultMethod(TypeStore t
             .setArguments(
                 MethodInvocationExpr.builder().setMethodName("getDefaultEndpoint").build())
             .build());
+    bodyExprs.add(
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(builderVarExpr)
+            .setMethodName("setMtlsEndpoint")
+            .setArguments(
+                MethodInvocationExpr.builder().setMethodName("getDefaultMtlsEndpoint").build())
+            .build());
+    bodyExprs.add(
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(builderVarExpr)
+            .setMethodName("setSwitchToMtlsEndpointAllowed")
+            .setArguments(
+                ValueExpr.withValue(
+                    PrimitiveValue.builder().setType(TypeNode.BOOLEAN).setValue("true").build()))
+            .build());
     bodyStatements.addAll(
         bodyExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
     bodyStatements.add(EMPTY_LINE_STATEMENT);
@@ -1609,7 +1854,7 @@ private static MethodDefinition createNestedClassCreateDefaultMethod(TypeStore t
         .setScope(ScopeNode.PRIVATE)
         .setIsStatic(true)
         .setReturnType(builderType)
-        .setName("createDefault")
+        .setName(methodName)
         .setBody(bodyStatements)
         .setReturnExpr(returnExpr)
         .build();
@@ -1650,7 +1895,6 @@ private static MethodDefinition createNestedClassApplyToAllUnaryMethodsMethod(
         .setReturnType(returnType)
         .setName(methodName)
         .setArguments(settingsUpdaterVarExpr.toBuilder().setIsDecl(true).build())
-        .setThrowsExceptions(Arrays.asList(TypeNode.withExceptionClazz(Exception.class)))
         .setBody(Arrays.asList(ExprStatement.withExpr(superApplyExpr)))
         .setReturnExpr(returnExpr)
         .build();
@@ -1737,7 +1981,7 @@ private static MethodDefinition createNestedClassBuildMethod(
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             ApiCallContext.class,
             ApiClientHeaderProvider.class,
@@ -1794,10 +2038,12 @@ private TypeStore createDynamicTypes(Service service, String pakkage) {
         pakkage,
         Arrays.asList(
             thisClassName,
-            getTransportContext().classNames().getTransportServiceStubClassName(service),
             ClassNames.getServiceStubSettingsClassName(service),
             ClassNames.getServiceStubClassName(service)));
 
+    typeStore.putAll(
+        pakkage, getTransportContext().classNames().getTransportServiceStubClassNames(service));
+
     // Nested builder class.
     typeStore.put(pakkage, NESTED_BUILDER_CLASS_NAME, true, thisClassName);
 
@@ -1893,7 +2139,7 @@ private static TypeNode getCallSettingsType(
       TypeStore typeStore,
       boolean isBatchingSettings,
       final boolean isSettingsBuilder) {
-    Function<Class, TypeNode> typeMakerFn =
+    Function<Class<?>, TypeNode> typeMakerFn =
         clz -> TypeNode.withReference(ConcreteReference.withClazz(clz));
     // Default: No streaming.
     TypeNode callSettingsType =
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/AbstractTransportServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractTransportServiceStubClassComposer.java
new file mode 100644
index 0000000000..7137f4f1fb
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/AbstractTransportServiceStubClassComposer.java
@@ -0,0 +1,1001 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.common;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.core.BackgroundResourceAggregation;
+import com.google.api.gax.rpc.BidiStreamingCallable;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientStreamingCallable;
+import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.RequestParamsExtractor;
+import com.google.api.gax.rpc.ServerStreamingCallable;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.api.generator.engine.ast.AnnotationNode;
+import com.google.api.generator.engine.ast.AssignmentExpr;
+import com.google.api.generator.engine.ast.ClassDefinition;
+import com.google.api.generator.engine.ast.CommentStatement;
+import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.EmptyLineStatement;
+import com.google.api.generator.engine.ast.Expr;
+import com.google.api.generator.engine.ast.ExprStatement;
+import com.google.api.generator.engine.ast.JavaDocComment;
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.NewObjectExpr;
+import com.google.api.generator.engine.ast.ReferenceConstructorExpr;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.ast.Statement;
+import com.google.api.generator.engine.ast.ThisObjectValue;
+import com.google.api.generator.engine.ast.ThrowExpr;
+import com.google.api.generator.engine.ast.TryCatchStatement;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.engine.ast.Variable;
+import com.google.api.generator.engine.ast.VariableExpr;
+import com.google.api.generator.gapic.composer.comment.StubCommentComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.composer.utils.ClassNames;
+import com.google.api.generator.gapic.composer.utils.PackageChecker;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicClass.Kind;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Method;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.utils.JavaStyle;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
+import com.google.longrunning.Operation;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import javax.annotation.Generated;
+
+public abstract class AbstractTransportServiceStubClassComposer implements ClassComposer {
+  private static final Statement EMPTY_LINE_STATEMENT = EmptyLineStatement.create();
+
+  private static final String METHOD_DESCRIPTOR_NAME_PATTERN = "%sMethodDescriptor";
+  private static final String PAGED_RESPONSE_TYPE_NAME_PATTERN = "%sPagedResponse";
+  private static final String PAGED_CALLABLE_CLASS_MEMBER_PATTERN = "%sPagedCallable";
+
+  private static final String BACKGROUND_RESOURCES_MEMBER_NAME = "backgroundResources";
+  private static final String CALLABLE_NAME = "Callable";
+  private static final String CALLABLE_FACTORY_MEMBER_NAME = "callableFactory";
+  private static final String CALLABLE_CLASS_MEMBER_PATTERN = "%sCallable";
+  private static final String OPERATION_CALLABLE_CLASS_MEMBER_PATTERN = "%sOperationCallable";
+  private static final String OPERATION_CALLABLE_NAME = "OperationCallable";
+  // private static final String OPERATIONS_STUB_MEMBER_NAME = "operationsStub";
+  private static final String PAGED_CALLABLE_NAME = "PagedCallable";
+
+  protected static final TypeStore FIXED_TYPESTORE = createStaticTypes();
+
+  private final TransportContext transportContext;
+
+  protected AbstractTransportServiceStubClassComposer(TransportContext transportContext) {
+    this.transportContext = transportContext;
+  }
+
+  public TransportContext getTransportContext() {
+    return transportContext;
+  }
+
+  private static TypeStore createStaticTypes() {
+    List<Class<?>> concreteClazzes =
+        Arrays.asList(
+            BackgroundResource.class,
+            BackgroundResourceAggregation.class,
+            BetaApi.class,
+            BidiStreamingCallable.class,
+            ClientContext.class,
+            ClientStreamingCallable.class,
+            Generated.class,
+            ImmutableMap.class,
+            InterruptedException.class,
+            IOException.class,
+            Operation.class,
+            OperationCallable.class,
+            RequestParamsExtractor.class,
+            ServerStreamingCallable.class,
+            TimeUnit.class,
+            UnaryCallable.class);
+    return new TypeStore(concreteClazzes);
+  }
+
+  @Override
+  public GapicClass generate(GapicContext context, Service service) {
+    String pakkage = service.pakkage() + ".stub";
+    TypeStore typeStore = createDynamicTypes(service, pakkage);
+    String className = getTransportContext().classNames().getTransportServiceStubClassName(service);
+    GapicClass.Kind kind = Kind.STUB;
+
+    Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs =
+        createProtoMethodNameToDescriptorClassMembers(
+            service, getTransportContext().methodDescriptorClass());
+
+    Map<String, VariableExpr> callableClassMemberVarExprs =
+        createCallableClassMembers(service, typeStore);
+
+    Map<String, VariableExpr> classMemberVarExprs = new LinkedHashMap<>();
+    classMemberVarExprs.put(
+        BACKGROUND_RESOURCES_MEMBER_NAME,
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setName(BACKGROUND_RESOURCES_MEMBER_NAME)
+                .setType(FIXED_TYPESTORE.get("BackgroundResource"))
+                .build()));
+    if (generateOperationsStubLogic(service)) {
+      // Transport-specific service stub may have only one element of the following, thus get(0).
+      classMemberVarExprs.put(
+          getTransportContext().transportOperationsStubNames().get(0),
+          VariableExpr.withVariable(
+              Variable.builder()
+                  .setName(getTransportContext().transportOperationsStubNames().get(0))
+                  .setType(getTransportContext().transportOperationsStubTypes().get(0))
+                  .build()));
+    }
+    classMemberVarExprs.put(
+        CALLABLE_FACTORY_MEMBER_NAME,
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setName(CALLABLE_FACTORY_MEMBER_NAME)
+                .setType(getTransportContext().stubCallableFactoryType())
+                .build()));
+
+    List<Statement> classStatements =
+        createClassStatements(
+            service,
+            protoMethodNameToDescriptorVarExprs,
+            callableClassMemberVarExprs,
+            classMemberVarExprs);
+
+    StubCommentComposer commentComposer =
+        new StubCommentComposer(getTransportContext().transportName());
+
+    ClassDefinition classDef =
+        ClassDefinition.builder()
+            .setPackageString(pakkage)
+            .setHeaderCommentStatements(
+                commentComposer.createTransportServiceStubClassHeaderComments(
+                    service.name(), service.isDeprecated()))
+            .setAnnotations(createClassAnnotations(service))
+            .setScope(ScopeNode.PUBLIC)
+            .setName(className)
+            .setExtendsType(typeStore.get(ClassNames.getServiceStubClassName(service)))
+            .setStatements(classStatements)
+            .setMethods(
+                createClassMethods(
+                    service,
+                    typeStore,
+                    classMemberVarExprs,
+                    callableClassMemberVarExprs,
+                    protoMethodNameToDescriptorVarExprs))
+            .build();
+    return GapicClass.create(kind, classDef);
+  }
+
+  protected abstract Statement createMethodDescriptorVariableDecl(
+      Service service, Method protoMethod, VariableExpr methodDescriptorVarExpr);
+
+  protected boolean generateOperationsStubLogic(Service service) {
+    return true;
+  }
+
+  protected List<MethodDefinition> createOperationsStubGetterMethod(
+      Service service, VariableExpr operationsStubVarExpr) {
+    if (!generateOperationsStubLogic(service)) {
+      return Collections.emptyList();
+    }
+
+    String methodName =
+        String.format(
+            "get%s",
+            JavaStyle.toUpperCamelCase(
+                getTransportContext().transportOperationsStubNames().get(0)));
+
+    return Arrays.asList(
+        MethodDefinition.builder()
+            .setScope(ScopeNode.PUBLIC)
+            .setReturnType(operationsStubVarExpr.type())
+            .setName(methodName)
+            .setReturnExpr(operationsStubVarExpr)
+            .build());
+  }
+
+  protected abstract Expr createTransportSettingsInitExpr(
+      Method method, VariableExpr transportSettingsVarExpr, VariableExpr methodDescriptorVarExpr);
+
+  protected List<MethodDefinition> createGetMethodDescriptorsMethod(
+      Service service,
+      TypeStore typeStore,
+      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
+    return Arrays.asList();
+  }
+
+  protected List<Statement> createClassStatements(
+      Service service,
+      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs,
+      Map<String, VariableExpr> callableClassMemberVarExprs,
+      Map<String, VariableExpr> classMemberVarExprs) {
+    List<Statement> classStatements = new ArrayList<>();
+    for (Statement statement :
+        createMethodDescriptorVariableDecls(service, protoMethodNameToDescriptorVarExprs)) {
+      classStatements.add(statement);
+      classStatements.add(EMPTY_LINE_STATEMENT);
+    }
+
+    classStatements.addAll(createClassMemberFieldDeclarations(callableClassMemberVarExprs));
+    classStatements.add(EMPTY_LINE_STATEMENT);
+
+    classStatements.addAll(createClassMemberFieldDeclarations(classMemberVarExprs));
+    return classStatements;
+  }
+
+  protected List<Statement> createMethodDescriptorVariableDecls(
+      Service service, Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
+    return service.methods().stream()
+        .map(
+            m ->
+                createMethodDescriptorVariableDecl(
+                    service, m, protoMethodNameToDescriptorVarExprs.get(m.name())))
+        .collect(Collectors.toList());
+  }
+
+  private static List<Statement> createClassMemberFieldDeclarations(
+      Map<String, VariableExpr> fieldNameToVarExprs) {
+    return fieldNameToVarExprs.values().stream()
+        .map(
+            v ->
+                ExprStatement.withExpr(
+                    v.toBuilder()
+                        .setIsDecl(true)
+                        .setScope(ScopeNode.PRIVATE)
+                        .setIsFinal(true)
+                        .build()))
+        .collect(Collectors.toList());
+  }
+
+  protected Map<String, VariableExpr> createProtoMethodNameToDescriptorClassMembers(
+      Service service, Class<?> descriptorClass) {
+    return service.methods().stream()
+        .collect(
+            Collectors.toMap(
+                Method::name,
+                m ->
+                    VariableExpr.withVariable(
+                        Variable.builder()
+                            .setName(
+                                String.format(
+                                    METHOD_DESCRIPTOR_NAME_PATTERN,
+                                    JavaStyle.toLowerCamelCase(m.name())))
+                            .setType(
+                                TypeNode.withReference(
+                                    ConcreteReference.builder()
+                                        .setClazz(descriptorClass)
+                                        .setGenerics(
+                                            Arrays.asList(
+                                                m.inputType().reference(),
+                                                m.outputType().reference()))
+                                        .build()))
+                            .build()),
+                (u, v) -> {
+                  throw new IllegalStateException();
+                },
+                LinkedHashMap::new));
+  }
+
+  private Map<String, VariableExpr> createCallableClassMembers(
+      Service service, TypeStore typeStore) {
+    Map<String, VariableExpr> callableClassMembers = new LinkedHashMap<>();
+    // Using a for-loop because the output cardinality is not a 1:1 mapping to the input set.
+    for (Method protoMethod : service.methods()) {
+      String javaStyleProtoMethodName = JavaStyle.toLowerCamelCase(protoMethod.name());
+      String callableName = String.format(CALLABLE_CLASS_MEMBER_PATTERN, javaStyleProtoMethodName);
+      callableClassMembers.put(
+          callableName,
+          VariableExpr.withVariable(
+              Variable.builder()
+                  .setName(callableName)
+                  .setType(getCallableType(protoMethod))
+                  .build()));
+      if (protoMethod.hasLro()) {
+        callableName =
+            String.format(OPERATION_CALLABLE_CLASS_MEMBER_PATTERN, javaStyleProtoMethodName);
+        callableClassMembers.put(
+            callableName,
+            VariableExpr.withVariable(
+                Variable.builder()
+                    .setName(callableName)
+                    .setType(
+                        TypeNode.withReference(
+                            ConcreteReference.builder()
+                                .setClazz(OperationCallable.class)
+                                .setGenerics(
+                                    Arrays.asList(
+                                        protoMethod.inputType().reference(),
+                                        protoMethod.lro().responseType().reference(),
+                                        protoMethod.lro().metadataType().reference()))
+                                .build()))
+                    .build()));
+      }
+      if (protoMethod.isPaged()) {
+        callableName = String.format(PAGED_CALLABLE_CLASS_MEMBER_PATTERN, javaStyleProtoMethodName);
+        callableClassMembers.put(
+            callableName,
+            VariableExpr.withVariable(
+                Variable.builder()
+                    .setName(callableName)
+                    .setType(
+                        TypeNode.withReference(
+                            getCallableType(protoMethod)
+                                .reference()
+                                .copyAndSetGenerics(
+                                    Arrays.asList(
+                                        protoMethod.inputType().reference(),
+                                        typeStore
+                                            .get(
+                                                String.format(
+                                                    PAGED_RESPONSE_TYPE_NAME_PATTERN,
+                                                    protoMethod.name()))
+                                            .reference()))))
+                    .build()));
+      }
+    }
+    return callableClassMembers;
+  }
+
+  protected List<AnnotationNode> createClassAnnotations(Service service) {
+    List<AnnotationNode> annotations = new ArrayList<>();
+    if (!PackageChecker.isGaApi(service.pakkage())) {
+      annotations.add(AnnotationNode.withType(FIXED_TYPESTORE.get("BetaApi")));
+    }
+
+    if (service.isDeprecated()) {
+      annotations.add(AnnotationNode.withType(TypeNode.DEPRECATED));
+    }
+
+    annotations.add(
+        AnnotationNode.builder()
+            .setType(FIXED_TYPESTORE.get("Generated"))
+            .setDescription("by gapic-generator-java")
+            .build());
+    return annotations;
+  }
+
+  protected List<MethodDefinition> createClassMethods(
+      Service service,
+      TypeStore typeStore,
+      Map<String, VariableExpr> classMemberVarExprs,
+      Map<String, VariableExpr> callableClassMemberVarExprs,
+      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
+    List<MethodDefinition> javaMethods = new ArrayList<>();
+    javaMethods.addAll(createStaticCreatorMethods(service, typeStore, "newBuilder"));
+    javaMethods.addAll(
+        createConstructorMethods(
+            service,
+            typeStore,
+            classMemberVarExprs,
+            callableClassMemberVarExprs,
+            protoMethodNameToDescriptorVarExprs));
+    javaMethods.addAll(
+        createGetMethodDescriptorsMethod(service, typeStore, protoMethodNameToDescriptorVarExprs));
+    javaMethods.addAll(
+        createOperationsStubGetterMethod(
+            service,
+            classMemberVarExprs.get(getTransportContext().transportOperationsStubNames().get(0))));
+    javaMethods.addAll(createCallableGetterMethods(callableClassMemberVarExprs));
+    javaMethods.addAll(
+        createStubOverrideMethods(classMemberVarExprs.get(BACKGROUND_RESOURCES_MEMBER_NAME)));
+    return javaMethods;
+  }
+
+  protected List<MethodDefinition> createStaticCreatorMethods(
+      Service service, TypeStore typeStore, String newBuilderMethod) {
+    TypeNode creatorMethodReturnType =
+        typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service));
+    Function<List<VariableExpr>, MethodDefinition.Builder> creatorMethodStarterFn =
+        argList ->
+            MethodDefinition.builder()
+                .setScope(ScopeNode.PUBLIC)
+                .setIsStatic(true)
+                .setIsFinal(true)
+                .setReturnType(creatorMethodReturnType)
+                .setName("create")
+                .setArguments(
+                    argList.stream()
+                        .map(v -> v.toBuilder().setIsDecl(true).build())
+                        .collect(Collectors.toList()))
+                .setThrowsExceptions(
+                    Arrays.asList(
+                        TypeNode.withReference(ConcreteReference.withClazz(IOException.class))));
+
+    Function<List<Expr>, Expr> instantiatorExprFn =
+        argList ->
+            NewObjectExpr.builder().setType(creatorMethodReturnType).setArguments(argList).build();
+
+    TypeNode stubSettingsType = typeStore.get(ClassNames.getServiceStubSettingsClassName(service));
+    VariableExpr settingsVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("settings").setType(stubSettingsType).build());
+
+    TypeNode clientContextType = FIXED_TYPESTORE.get("ClientContext");
+    VariableExpr clientContextVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("clientContext").setType(clientContextType).build());
+
+    VariableExpr callableFactoryVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setName("callableFactory")
+                .setType(getTransportContext().stubCallableFactoryType())
+                .build());
+
+    MethodInvocationExpr clientContextCreateMethodExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("create")
+            .setStaticReferenceType(clientContextType)
+            .setArguments(Arrays.asList(settingsVarExpr))
+            .build();
+    MethodInvocationExpr settingsBuilderMethodExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName(newBuilderMethod)
+            .setStaticReferenceType(stubSettingsType)
+            .build();
+    settingsBuilderMethodExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("build")
+            .setExprReferenceExpr(settingsBuilderMethodExpr)
+            .build();
+
+    return Arrays.asList(
+        creatorMethodStarterFn
+            .apply(Arrays.asList(settingsVarExpr))
+            .setReturnExpr(
+                instantiatorExprFn.apply(
+                    Arrays.asList(settingsVarExpr, clientContextCreateMethodExpr)))
+            .build(),
+        creatorMethodStarterFn
+            .apply(Arrays.asList(clientContextVarExpr))
+            .setReturnExpr(
+                instantiatorExprFn.apply(
+                    Arrays.asList(settingsBuilderMethodExpr, clientContextVarExpr)))
+            .build(),
+        creatorMethodStarterFn
+            .apply(Arrays.asList(clientContextVarExpr, callableFactoryVarExpr))
+            .setReturnExpr(
+                instantiatorExprFn.apply(
+                    Arrays.asList(
+                        settingsBuilderMethodExpr, clientContextVarExpr, callableFactoryVarExpr)))
+            .build());
+  }
+
+  protected List<MethodDefinition> createConstructorMethods(
+      Service service,
+      TypeStore typeStore,
+      Map<String, VariableExpr> classMemberVarExprs,
+      Map<String, VariableExpr> callableClassMemberVarExprs,
+      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
+    TypeNode stubSettingsType = typeStore.get(ClassNames.getServiceStubSettingsClassName(service));
+    VariableExpr settingsVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("settings").setType(stubSettingsType).build());
+
+    TypeNode clientContextType = FIXED_TYPESTORE.get("ClientContext");
+    VariableExpr clientContextVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("clientContext").setType(clientContextType).build());
+
+    VariableExpr callableFactoryVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setName("callableFactory")
+                .setType(getTransportContext().stubCallableFactoryType())
+                .build());
+
+    TypeNode thisClassType =
+        typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service));
+    TypeNode ioExceptionType =
+        TypeNode.withReference(ConcreteReference.withClazz(IOException.class));
+
+    BiFunction<List<VariableExpr>, List<Statement>, MethodDefinition> ctorMakerFn =
+        (args, body) ->
+            MethodDefinition.constructorBuilder()
+                .setScope(ScopeNode.PROTECTED)
+                .setReturnType(thisClassType)
+                .setHeaderCommentStatements(Arrays.asList(createProtectedCtorComment(service)))
+                .setArguments(
+                    args.stream()
+                        .map(v -> v.toBuilder().setIsDecl(true).build())
+                        .collect(Collectors.toList()))
+                .setThrowsExceptions(Arrays.asList(ioExceptionType))
+                .setBody(body)
+                .build();
+
+    // First constructor method.
+    MethodDefinition firstCtor =
+        ctorMakerFn.apply(
+            Arrays.asList(settingsVarExpr, clientContextVarExpr),
+            Arrays.asList(
+                ExprStatement.withExpr(
+                    ReferenceConstructorExpr.thisBuilder()
+                        .setType(thisClassType)
+                        .setArguments(
+                            settingsVarExpr,
+                            clientContextVarExpr,
+                            NewObjectExpr.builder()
+                                .setType(
+                                    typeStore.get(
+                                        getTransportContext()
+                                            .classNames()
+                                            .getTransportServiceCallableFactoryClassName(service)))
+                                .build())
+                        .build())));
+
+    Expr thisExpr =
+        ValueExpr.withValue(
+            ThisObjectValue.withType(
+                typeStore.get(
+                    getTransportContext().classNames().getTransportServiceStubClassName(service))));
+    // Body of the second constructor method.
+    List<Statement> secondCtorStatements = new ArrayList<>();
+    List<Expr> secondCtorExprs = new ArrayList<>();
+    secondCtorExprs.add(
+        AssignmentExpr.builder()
+            .setVariableExpr(
+                classMemberVarExprs.get("callableFactory").toBuilder()
+                    .setExprReferenceExpr(thisExpr)
+                    .build())
+            .setValueExpr(callableFactoryVarExpr)
+            .build());
+    VariableExpr operationsStubClassVarExpr =
+        classMemberVarExprs.get(getTransportContext().transportOperationsStubNames().get(0));
+    if (generateOperationsStubLogic(service)) {
+      secondCtorExprs.add(
+          AssignmentExpr.builder()
+              .setVariableExpr(
+                  operationsStubClassVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
+              .setValueExpr(
+                  MethodInvocationExpr.builder()
+                      .setStaticReferenceType(
+                          getTransportContext().transportOperationsStubTypes().get(0))
+                      .setMethodName("create")
+                      .setArguments(Arrays.asList(clientContextVarExpr, callableFactoryVarExpr))
+                      .setReturnType(operationsStubClassVarExpr.type())
+                      .build())
+              .build());
+    }
+    secondCtorStatements.addAll(
+        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
+    secondCtorExprs.clear();
+    secondCtorStatements.add(EMPTY_LINE_STATEMENT);
+
+    // Transport settings local variables.
+    Map<String, VariableExpr> javaStyleMethodNameToTransportSettingsVarExprs =
+        service.methods().stream()
+            .collect(
+                Collectors.toMap(
+                    m -> JavaStyle.toLowerCamelCase(m.name()),
+                    m ->
+                        VariableExpr.withVariable(
+                            Variable.builder()
+                                .setName(
+                                    String.format(
+                                        "%sTransportSettings",
+                                        JavaStyle.toLowerCamelCase(m.name())))
+                                .setType(
+                                    TypeNode.withReference(
+                                        ConcreteReference.builder()
+                                            .setClazz(getTransportContext().callSettingsClass())
+                                            .setGenerics(
+                                                Arrays.asList(
+                                                    m.inputType().reference(),
+                                                    m.outputType().reference()))
+                                            .build()))
+                                .build())));
+
+    secondCtorExprs.addAll(
+        service.methods().stream()
+            .map(
+                m ->
+                    createTransportSettingsInitExpr(
+                        m,
+                        javaStyleMethodNameToTransportSettingsVarExprs.get(
+                            JavaStyle.toLowerCamelCase(m.name())),
+                        protoMethodNameToDescriptorVarExprs.get(m.name())))
+            .collect(Collectors.toList()));
+    secondCtorStatements.addAll(
+        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
+    secondCtorExprs.clear();
+    secondCtorStatements.add(EMPTY_LINE_STATEMENT);
+
+    // Initialize <method>Callable variables.
+    secondCtorExprs.addAll(
+        callableClassMemberVarExprs.entrySet().stream()
+            .map(
+                e ->
+                    createCallableInitExpr(
+                        e.getKey(),
+                        e.getValue(),
+                        callableFactoryVarExpr,
+                        settingsVarExpr,
+                        clientContextVarExpr,
+                        operationsStubClassVarExpr,
+                        thisExpr,
+                        javaStyleMethodNameToTransportSettingsVarExprs))
+            .collect(Collectors.toList()));
+    secondCtorStatements.addAll(
+        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
+    secondCtorExprs.clear();
+    secondCtorStatements.add(EMPTY_LINE_STATEMENT);
+
+    // Instantiate backgroundResources.
+    MethodInvocationExpr getBackgroundResourcesMethodExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(clientContextVarExpr)
+            .setMethodName("getBackgroundResources")
+            .build();
+    VariableExpr backgroundResourcesVarExpr = classMemberVarExprs.get("backgroundResources");
+    secondCtorExprs.add(
+        AssignmentExpr.builder()
+            .setVariableExpr(
+                backgroundResourcesVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
+            .setValueExpr(
+                NewObjectExpr.builder()
+                    .setType(FIXED_TYPESTORE.get("BackgroundResourceAggregation"))
+                    .setArguments(Arrays.asList(getBackgroundResourcesMethodExpr))
+                    .build())
+            .build());
+    secondCtorStatements.addAll(
+        secondCtorExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()));
+    secondCtorExprs.clear();
+
+    // Second constructor method.
+    MethodDefinition secondCtor =
+        ctorMakerFn.apply(
+            Arrays.asList(settingsVarExpr, clientContextVarExpr, callableFactoryVarExpr),
+            secondCtorStatements);
+
+    return Arrays.asList(firstCtor, secondCtor);
+  }
+
+  private Expr createCallableInitExpr(
+      String callableVarName,
+      VariableExpr callableVarExpr,
+      VariableExpr callableFactoryVarExpr,
+      VariableExpr settingsVarExpr,
+      VariableExpr clientContextVarExpr,
+      VariableExpr operationsStubClassVarExpr,
+      Expr thisExpr,
+      Map<String, VariableExpr> javaStyleMethodNameToTransportSettingsVarExprs) {
+    boolean isOperation = callableVarName.endsWith(OPERATION_CALLABLE_NAME);
+    boolean isPaged = callableVarName.endsWith(PAGED_CALLABLE_NAME);
+    int sublength = 0;
+    if (isOperation) {
+      sublength = OPERATION_CALLABLE_NAME.length();
+    } else if (isPaged) {
+      sublength = PAGED_CALLABLE_NAME.length();
+    } else {
+      sublength = CALLABLE_NAME.length();
+    }
+    String javaStyleMethodName = callableVarName.substring(0, callableVarName.length() - sublength);
+    List<Expr> creatorMethodArgVarExprs = null;
+    Expr transportSettingsVarExpr =
+        javaStyleMethodNameToTransportSettingsVarExprs.get(javaStyleMethodName);
+    if (transportSettingsVarExpr == null && isOperation) {
+      // Try again, in case the name dtection above was inaccurate.
+      isOperation = false;
+      sublength = CALLABLE_NAME.length();
+      javaStyleMethodName = callableVarName.substring(0, callableVarName.length() - sublength);
+      transportSettingsVarExpr =
+          javaStyleMethodNameToTransportSettingsVarExprs.get(javaStyleMethodName);
+    }
+    Preconditions.checkNotNull(
+        transportSettingsVarExpr,
+        String.format(
+            "No transport settings variable found for method name %s", javaStyleMethodName));
+    if (isOperation) {
+      creatorMethodArgVarExprs =
+          Arrays.asList(
+              transportSettingsVarExpr,
+              MethodInvocationExpr.builder()
+                  .setExprReferenceExpr(settingsVarExpr)
+                  .setMethodName(String.format("%sOperationSettings", javaStyleMethodName))
+                  .build(),
+              clientContextVarExpr,
+              operationsStubClassVarExpr);
+    } else {
+      creatorMethodArgVarExprs =
+          Arrays.asList(
+              transportSettingsVarExpr,
+              MethodInvocationExpr.builder()
+                  .setExprReferenceExpr(settingsVarExpr)
+                  .setMethodName(String.format("%sSettings", javaStyleMethodName))
+                  .build(),
+              clientContextVarExpr);
+    }
+
+    Optional<String> callableCreatorMethodName =
+        getCallableCreatorMethodName(callableVarExpr.type());
+
+    Expr initExpr;
+    if (callableCreatorMethodName.isPresent()) {
+      initExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(callableFactoryVarExpr)
+              .setMethodName(callableCreatorMethodName.get())
+              .setArguments(creatorMethodArgVarExprs)
+              .setReturnType(callableVarExpr.type())
+              .build();
+    } else {
+      initExpr = ValueExpr.createNullExpr();
+    }
+
+    return AssignmentExpr.builder()
+        .setVariableExpr(callableVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build())
+        .setValueExpr(initExpr)
+        .build();
+  }
+
+  protected Optional<String> getCallableCreatorMethodName(TypeNode callableVarExprType) {
+    final String typeName = callableVarExprType.reference().name();
+    String streamName = "Unary";
+
+    // Special handling for pagination methods.
+    if (callableVarExprType.reference().generics().size() == 2
+        && callableVarExprType.reference().generics().get(1).name().endsWith("PagedResponse")) {
+      streamName = "Paged";
+    } else {
+      if (typeName.startsWith("Client")) {
+        streamName = "ClientStreaming";
+      } else if (typeName.startsWith("Server")) {
+        streamName = "ServerStreaming";
+      } else if (typeName.startsWith("Bidi")) {
+        streamName = "BidiStreaming";
+      } else if (typeName.startsWith("Operation")) {
+        streamName = "Operation";
+      }
+    }
+    return Optional.of(String.format("create%sCallable", streamName));
+  }
+
+  private static List<MethodDefinition> createCallableGetterMethods(
+      Map<String, VariableExpr> callableClassMemberVarExprs) {
+    return callableClassMemberVarExprs.entrySet().stream()
+        .map(
+            e ->
+                MethodDefinition.builder()
+                    .setIsOverride(true)
+                    .setScope(ScopeNode.PUBLIC)
+                    .setReturnType(e.getValue().type())
+                    .setName(e.getKey())
+                    .setReturnExpr(e.getValue())
+                    .build())
+        .collect(Collectors.toList());
+  }
+
+  private List<MethodDefinition> createStubOverrideMethods(
+      VariableExpr backgroundResourcesVarExpr) {
+    Function<String, MethodDefinition.Builder> methodMakerStarterFn =
+        methodName ->
+            MethodDefinition.builder()
+                .setIsOverride(true)
+                .setScope(ScopeNode.PUBLIC)
+                .setName(methodName);
+
+    Function<String, MethodDefinition> voidMethodMakerFn =
+        methodName ->
+            methodMakerStarterFn
+                .apply(methodName)
+                .setReturnType(TypeNode.VOID)
+                .setBody(
+                    Arrays.asList(
+                        ExprStatement.withExpr(
+                            MethodInvocationExpr.builder()
+                                .setExprReferenceExpr(backgroundResourcesVarExpr)
+                                .setMethodName(methodName)
+                                .build())))
+                .build();
+
+    Function<String, MethodDefinition> booleanMethodMakerFn =
+        methodName ->
+            methodMakerStarterFn
+                .apply(methodName)
+                .setReturnType(TypeNode.BOOLEAN)
+                .setReturnExpr(
+                    MethodInvocationExpr.builder()
+                        .setExprReferenceExpr(backgroundResourcesVarExpr)
+                        .setMethodName(methodName)
+                        .setReturnType(TypeNode.BOOLEAN)
+                        .build())
+                .build();
+
+    // Generate the close() method:
+    //   @Override
+    //   public final void close() {
+    //     try {
+    //       backgroundResources.close();
+    //     } catch (RuntimeException e) {
+    //       throw e;
+    //     } catch (Exception e) {
+    //       throw new IllegalStateException("Failed to close resource", e);
+    //     }
+    //  }
+
+    VariableExpr catchRuntimeExceptionVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                Variable.builder()
+                    .setType(TypeNode.withExceptionClazz(RuntimeException.class))
+                    .setName("e")
+                    .build())
+            .build();
+    VariableExpr catchExceptionVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                Variable.builder()
+                    .setType(TypeNode.withExceptionClazz(Exception.class))
+                    .setName("e")
+                    .build())
+            .build();
+    List<MethodDefinition> javaMethods = new ArrayList<>();
+    javaMethods.add(
+        methodMakerStarterFn
+            .apply("close")
+            .setIsFinal(true)
+            .setReturnType(TypeNode.VOID)
+            .setBody(
+                Arrays.asList(
+                    TryCatchStatement.builder()
+                        .setTryBody(
+                            Arrays.asList(
+                                ExprStatement.withExpr(
+                                    MethodInvocationExpr.builder()
+                                        .setExprReferenceExpr(backgroundResourcesVarExpr)
+                                        .setMethodName("close")
+                                        .build())))
+                        .addCatch(
+                            catchRuntimeExceptionVarExpr.toBuilder().setIsDecl(true).build(),
+                            Arrays.asList(
+                                ExprStatement.withExpr(
+                                    ThrowExpr.builder()
+                                        .setThrowExpr(catchRuntimeExceptionVarExpr)
+                                        .build())))
+                        .addCatch(
+                            catchExceptionVarExpr.toBuilder().setIsDecl(true).build(),
+                            Arrays.asList(
+                                ExprStatement.withExpr(
+                                    ThrowExpr.builder()
+                                        .setType(
+                                            TypeNode.withExceptionClazz(
+                                                IllegalStateException.class))
+                                        .setMessageExpr(String.format("Failed to close resource"))
+                                        .setCauseExpr(catchExceptionVarExpr)
+                                        .build())))
+                        .build()))
+            .build());
+    javaMethods.add(voidMethodMakerFn.apply("shutdown"));
+    javaMethods.add(booleanMethodMakerFn.apply("isShutdown"));
+    javaMethods.add(booleanMethodMakerFn.apply("isTerminated"));
+    javaMethods.add(voidMethodMakerFn.apply("shutdownNow"));
+
+    List<VariableExpr> awaitTerminationArgs =
+        Arrays.asList(
+            VariableExpr.withVariable(
+                Variable.builder().setName("duration").setType(TypeNode.LONG).build()),
+            VariableExpr.withVariable(
+                Variable.builder()
+                    .setName("unit")
+                    .setType(FIXED_TYPESTORE.get("TimeUnit"))
+                    .build()));
+    javaMethods.add(
+        methodMakerStarterFn
+            .apply("awaitTermination")
+            .setReturnType(TypeNode.BOOLEAN)
+            .setArguments(
+                awaitTerminationArgs.stream()
+                    .map(v -> v.toBuilder().setIsDecl(true).build())
+                    .collect(Collectors.toList()))
+            .setThrowsExceptions(Arrays.asList(FIXED_TYPESTORE.get("InterruptedException")))
+            .setReturnExpr(
+                MethodInvocationExpr.builder()
+                    .setExprReferenceExpr(backgroundResourcesVarExpr)
+                    .setMethodName("awaitTermination")
+                    .setArguments(
+                        awaitTerminationArgs.stream()
+                            .map(v -> (Expr) v)
+                            .collect(Collectors.toList()))
+                    .setReturnType(TypeNode.BOOLEAN)
+                    .build())
+            .build());
+    return javaMethods;
+  }
+
+  private TypeStore createDynamicTypes(Service service, String stubPakkage) {
+    TypeStore typeStore = new TypeStore();
+    typeStore.putAll(
+        stubPakkage,
+        Arrays.asList(
+            getTransportContext().classNames().getTransportServiceStubClassName(service),
+            ClassNames.getServiceStubSettingsClassName(service),
+            ClassNames.getServiceStubClassName(service),
+            getTransportContext()
+                .classNames()
+                .getTransportServiceCallableFactoryClassName(service)));
+    // Pagination types.
+    typeStore.putAll(
+        service.pakkage(),
+        service.methods().stream()
+            .filter(m -> m.isPaged())
+            .map(m -> String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, m.name()))
+            .collect(Collectors.toList()),
+        true,
+        ClassNames.getServiceClientClassName(service));
+    return typeStore;
+  }
+
+  private static TypeNode getCallableType(Method protoMethod) {
+    TypeNode callableType = FIXED_TYPESTORE.get("UnaryCallable");
+    switch (protoMethod.stream()) {
+      case CLIENT:
+        callableType = FIXED_TYPESTORE.get("ClientStreamingCallable");
+        break;
+      case SERVER:
+        callableType = FIXED_TYPESTORE.get("ServerStreamingCallable");
+        break;
+      case BIDI:
+        callableType = FIXED_TYPESTORE.get("BidiStreamingCallable");
+        break;
+      case NONE:
+        // Fall through
+      default:
+        // Fall through
+    }
+
+    return TypeNode.withReference(
+        callableType
+            .reference()
+            .copyAndSetGenerics(
+                Arrays.asList(
+                    protoMethod.inputType().reference(), protoMethod.outputType().reference())));
+  }
+
+  private CommentStatement createProtectedCtorComment(Service service) {
+    return CommentStatement.withComment(
+        JavaDocComment.withComment(
+            String.format(
+                "Constructs an instance of %s, using the given settings. This is protected so that"
+                    + " it is easy to make a subclass, but otherwise, the static factory methods"
+                    + " should be  preferred.",
+                getTransportContext().classNames().getTransportServiceStubClassName(service))));
+  }
+
+  protected String getProtoRpcFullMethodName(Service protoService, Method protoMethod) {
+    if (protoMethod.isMixin()) {
+      return String.format("%s/%s", protoMethod.mixedInApiName(), protoMethod.name());
+    }
+
+    return String.format(
+        "%s.%s/%s", protoService.protoPakkage(), protoService.name(), protoMethod.name());
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposer.java
index 8de7d4c9c2..dc96c7bc43 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposer.java
@@ -66,7 +66,6 @@ public class BatchingDescriptorComposer {
   private static final TypeNode PARTITION_KEY_TYPE = toType(PartitionKey.class);
 
   private static final String ADD_ALL_METHOD_PATTERN = "addAll%s";
-  private static final String BATCH_FOO_INDEX_PATTERN = "batch%sIndex";
   private static final String GET_LIST_METHOD_PATTERN = "get%sList";
   private static final String GET_COUNT_METHOD_PATTERN = "get%sCount";
 
@@ -231,8 +230,7 @@ private static MethodDefinition createGetRequestBuilderMethod(
             .setStatements(
                 Arrays.asList(
                     ExprStatement.withExpr(
-                        builderVarExpr
-                            .toBuilder()
+                        builderVarExpr.toBuilder()
                             .setIsDecl(true)
                             .setScope(ScopeNode.PRIVATE)
                             .build())))
@@ -272,8 +270,6 @@ private static MethodDefinition createSplitResponseMethod(
         VariableExpr.withVariable(
             Variable.builder().setType(batchedRequestIssuerType).setName("responder").build());
 
-    String upperCamelBatchedFieldName =
-        JavaStyle.toUpperCamelCase(batchingSettings.batchedFieldName());
     VariableExpr batchMessageIndexVarExpr =
         VariableExpr.withVariable(
             Variable.builder().setType(TypeNode.INT).setName("batchMessageIndex").build());
@@ -541,7 +537,7 @@ private static MethodDefinition createCountByteSMethod(Method method) {
         .build();
   }
 
-  private static TypeNode toType(Class clazz) {
+  private static TypeNode toType(Class<?> clazz) {
     return TypeNode.withReference(ConcreteReference.withClazz(clazz));
   }
 
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposer.java
index 4a20961399..e5e4ad4195 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposer.java
@@ -248,7 +248,9 @@ public static Expr createLroSettingsBuilderExpr(
       Method method,
       VariableExpr builderVarExpr,
       VariableExpr retryableCodeDefsVarExpr,
-      VariableExpr retryParamDefsVarExpr) {
+      VariableExpr retryParamDefsVarExpr,
+      TypeNode operationResponseTransformer,
+      TypeNode operationMetadataTransformer) {
     Preconditions.checkState(
         method.hasLro(),
         String.format(
@@ -325,10 +327,7 @@ public static Expr createLroSettingsBuilderExpr(
             .setMethodName("setResponseTransformer")
             .setArguments(
                 MethodInvocationExpr.builder()
-                    .setStaticReferenceType(
-                        TypeNode.withReference(
-                            ConcreteReference.withClazz(
-                                ProtoOperationTransformers.ResponseTransformer.class)))
+                    .setStaticReferenceType(operationResponseTransformer)
                     .setMethodName("create")
                     .setArguments(classFieldRefFn.apply(method.lro().responseType()))
                     .build())
@@ -339,10 +338,7 @@ public static Expr createLroSettingsBuilderExpr(
             .setMethodName("setMetadataTransformer")
             .setArguments(
                 MethodInvocationExpr.builder()
-                    .setStaticReferenceType(
-                        TypeNode.withReference(
-                            ConcreteReference.withClazz(
-                                ProtoOperationTransformers.MetadataTransformer.class)))
+                    .setStaticReferenceType(operationMetadataTransformer)
                     .setMethodName("create")
                     .setArguments(classFieldRefFn.apply(method.lro().metadataType()))
                     .build())
@@ -715,7 +711,7 @@ private static MethodInvocationExpr createDurationOfMillisExpr(ValueExpr valExpr
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             BatchingSettings.class,
             org.threeten.bp.Duration.class,
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/ServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/common/ServiceStubClassComposer.java
deleted file mode 100644
index 9d16f98f88..0000000000
--- a/src/main/java/com/google/api/generator/gapic/composer/common/ServiceStubClassComposer.java
+++ /dev/null
@@ -1,279 +0,0 @@
-// Copyright 2020 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.api.generator.gapic.composer.common;
-
-import com.google.api.core.BetaApi;
-import com.google.api.gax.core.BackgroundResource;
-import com.google.api.gax.rpc.BidiStreamingCallable;
-import com.google.api.gax.rpc.ClientStreamingCallable;
-import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.ServerStreamingCallable;
-import com.google.api.gax.rpc.UnaryCallable;
-import com.google.api.generator.engine.ast.AnnotationNode;
-import com.google.api.generator.engine.ast.ClassDefinition;
-import com.google.api.generator.engine.ast.ExprStatement;
-import com.google.api.generator.engine.ast.MethodDefinition;
-import com.google.api.generator.engine.ast.Reference;
-import com.google.api.generator.engine.ast.ScopeNode;
-import com.google.api.generator.engine.ast.Statement;
-import com.google.api.generator.engine.ast.ThrowExpr;
-import com.google.api.generator.engine.ast.TypeNode;
-import com.google.api.generator.gapic.composer.comment.StubCommentComposer;
-import com.google.api.generator.gapic.composer.store.TypeStore;
-import com.google.api.generator.gapic.composer.utils.ClassNames;
-import com.google.api.generator.gapic.composer.utils.PackageChecker;
-import com.google.api.generator.gapic.model.GapicClass;
-import com.google.api.generator.gapic.model.GapicClass.Kind;
-import com.google.api.generator.gapic.model.GapicContext;
-import com.google.api.generator.gapic.model.Message;
-import com.google.api.generator.gapic.model.Method;
-import com.google.api.generator.gapic.model.Service;
-import com.google.api.generator.gapic.utils.JavaStyle;
-import com.google.longrunning.Operation;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.stream.Collectors;
-import javax.annotation.Generated;
-
-public class ServiceStubClassComposer implements ClassComposer {
-  private static final ServiceStubClassComposer INSTANCE = new ServiceStubClassComposer();
-  private static final String DOT = ".";
-  private static final String PAGED_RESPONSE_TYPE_NAME_PATTERN = "%sPagedResponse";
-
-  private ServiceStubClassComposer() {}
-
-  public static ServiceStubClassComposer instance() {
-    return INSTANCE;
-  }
-
-  @Override
-  public GapicClass generate(GapicContext context, Service service) {
-    Map<String, Message> messageTypes = context.messages();
-    TypeStore typeStore = createTypes(service, messageTypes);
-    String className = ClassNames.getServiceStubClassName(service);
-    GapicClass.Kind kind = Kind.STUB;
-    String pakkage = String.format("%s.stub", service.pakkage());
-
-    ClassDefinition classDef =
-        ClassDefinition.builder()
-            .setPackageString(pakkage)
-            .setHeaderCommentStatements(
-                StubCommentComposer.createServiceStubClassHeaderComments(
-                    service.name(), service.isDeprecated()))
-            .setAnnotations(createClassAnnotations(service, typeStore))
-            .setIsAbstract(true)
-            .setImplementsTypes(createClassImplements(typeStore))
-            .setName(className)
-            .setMethods(createClassMethods(service, messageTypes, typeStore))
-            .setScope(ScopeNode.PUBLIC)
-            .build();
-    return GapicClass.create(kind, classDef);
-  }
-
-  private static List<AnnotationNode> createClassAnnotations(Service service, TypeStore typeStore) {
-    List<AnnotationNode> annotations = new ArrayList<>();
-    if (!PackageChecker.isGaApi(service.pakkage())) {
-      annotations.add(AnnotationNode.withType(typeStore.get("BetaApi")));
-    }
-
-    if (service.isDeprecated()) {
-      annotations.add(AnnotationNode.withType(TypeNode.DEPRECATED));
-    }
-
-    annotations.add(
-        AnnotationNode.builder()
-            .setType(typeStore.get("Generated"))
-            .setDescription("by gapic-generator-java")
-            .build());
-    return annotations;
-  }
-
-  private static List<TypeNode> createClassImplements(TypeStore typeStore) {
-    return Arrays.asList(typeStore.get("BackgroundResource"));
-  }
-
-  private static List<MethodDefinition> createClassMethods(
-      Service service, Map<String, Message> messageTypes, TypeStore typeStore) {
-    boolean hasLroClient = hasLroMethods(service);
-    List<MethodDefinition> methods = new ArrayList<>();
-    if (hasLroClient) {
-      methods.add(createOperationsStubGetter(typeStore));
-    }
-    methods.addAll(createCallableGetters(service, messageTypes, typeStore));
-    methods.addAll(createBackgroundResourceMethodOverrides());
-    return methods;
-  }
-
-  private static List<MethodDefinition> createCallableGetters(
-      Service service, Map<String, Message> messageTypes, TypeStore typeStore) {
-    // Use a traditional for-loop since the output cardinality is not necessarily 1:1 with that of
-    // service.methods().
-    List<MethodDefinition> javaMethods = new ArrayList<>();
-    for (Method method : service.methods()) {
-      if (method.hasLro()) {
-        javaMethods.add(createOperationCallableGetter(method, typeStore));
-      }
-      if (method.isPaged()) {
-        javaMethods.add(createPagedCallableGetter(method, typeStore));
-      }
-      javaMethods.add(createCallableGetter(method, typeStore));
-    }
-    return javaMethods;
-  }
-
-  private static MethodDefinition createOperationCallableGetter(
-      Method method, TypeStore typeStore) {
-    return createCallableGetterHelper(method, typeStore, true, false);
-  }
-
-  private static MethodDefinition createPagedCallableGetter(Method method, TypeStore typeStore) {
-    return createCallableGetterHelper(method, typeStore, false, true);
-  }
-
-  private static MethodDefinition createCallableGetter(Method method, TypeStore typeStore) {
-    return createCallableGetterHelper(method, typeStore, false, false);
-  }
-
-  private static MethodDefinition createCallableGetterHelper(
-      Method method, TypeStore typeStore, boolean isLroCallable, boolean isPaged) {
-    TypeNode returnType;
-    switch (method.stream()) {
-      case CLIENT:
-        returnType = typeStore.get("ClientStreamingCallable");
-        break;
-      case SERVER:
-        returnType = typeStore.get("ServerStreamingCallable");
-        break;
-      case BIDI:
-        returnType = typeStore.get("BidiStreamingCallable");
-        break;
-      case NONE:
-        // Fall through.
-      default:
-        returnType = typeStore.get(isLroCallable ? "OperationCallable" : "UnaryCallable");
-    }
-
-    String methodName =
-        String.format(
-            "%s%sCallable",
-            JavaStyle.toLowerCamelCase(method.name()),
-            (isLroCallable ? "Operation" : isPaged ? "Paged" : ""));
-    List<Reference> genericRefs = new ArrayList<>();
-    genericRefs.add(method.inputType().reference());
-    if (method.hasLro() && isLroCallable) {
-      genericRefs.add(method.lro().responseType().reference());
-      genericRefs.add(method.lro().metadataType().reference());
-    } else if (isPaged) {
-      genericRefs.add(
-          typeStore
-              .get(String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, method.name()))
-              .reference());
-    } else {
-      genericRefs.add(method.outputType().reference());
-    }
-
-    List<AnnotationNode> annotations =
-        method.isDeprecated()
-            ? Arrays.asList(AnnotationNode.withType(TypeNode.DEPRECATED))
-            : Collections.emptyList();
-
-    returnType = TypeNode.withReference(returnType.reference().copyAndSetGenerics(genericRefs));
-
-    return MethodDefinition.builder()
-        .setAnnotations(annotations)
-        .setScope(ScopeNode.PUBLIC)
-        .setReturnType(returnType)
-        .setName(methodName)
-        .setBody(createThrowUOEBody(methodName, typeStore))
-        .build();
-  }
-
-  private static MethodDefinition createOperationsStubGetter(TypeStore typeStore) {
-    String methodName = "getOperationsStub";
-    return MethodDefinition.builder()
-        .setScope(ScopeNode.PUBLIC)
-        .setReturnType(typeStore.get("OperationsStub"))
-        .setName(methodName)
-        .setBody(createThrowUOEBody(methodName, typeStore))
-        .build();
-  }
-
-  private static List<MethodDefinition> createBackgroundResourceMethodOverrides() {
-    MethodDefinition closeMethod =
-        MethodDefinition.builder()
-            .setIsOverride(true)
-            .setScope(ScopeNode.PUBLIC)
-            .setIsAbstract(true)
-            .setReturnType(TypeNode.VOID)
-            .setName("close")
-            .build();
-    return Arrays.asList(closeMethod);
-  }
-
-  private static boolean hasLroMethods(Service service) {
-    for (Method method : service.methods()) {
-      if (method.hasLro()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  private static TypeStore createTypes(Service service, Map<String, Message> messageTypes) {
-    List<Class> concreteClazzes =
-        Arrays.asList(
-            BackgroundResource.class,
-            BetaApi.class,
-            BidiStreamingCallable.class,
-            ClientStreamingCallable.class,
-            Generated.class,
-            Operation.class,
-            OperationCallable.class,
-            ServerStreamingCallable.class,
-            UnaryCallable.class,
-            UnsupportedOperationException.class);
-    TypeStore typeStore = new TypeStore(concreteClazzes);
-
-    typeStore.put("com.google.longrunning.stub", "OperationsStub");
-
-    // Pagination types.
-    typeStore.putAll(
-        service.pakkage(),
-        service.methods().stream()
-            .filter(m -> m.isPaged())
-            .map(m -> String.format(PAGED_RESPONSE_TYPE_NAME_PATTERN, m.name()))
-            .collect(Collectors.toList()),
-        true,
-        ClassNames.getServiceClientClassName(service));
-
-    return typeStore;
-  }
-
-  private static List<Statement> createThrowUOEBody(String methodName, TypeStore typeStore) {
-    return Arrays.asList(
-        ExprStatement.withExpr(
-            ThrowExpr.builder()
-                .setType(typeStore.get("UnsupportedOperationException"))
-                .setMessageExpr(String.format("Not implemented: %s()", methodName))
-                .build()));
-  }
-
-  private static String getClientClassName(Service service) {
-    return String.format("%sClient", service.overriddenName());
-  }
-}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/common/TransportContext.java b/src/main/java/com/google/api/generator/gapic/composer/common/TransportContext.java
index 4058fbafbf..507ff662ca 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/common/TransportContext.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/common/TransportContext.java
@@ -19,6 +19,7 @@
 import com.google.api.generator.gapic.composer.utils.ClassNames;
 import com.google.api.generator.gapic.model.Transport;
 import com.google.auto.value.AutoValue;
+import java.util.List;
 import javax.annotation.Nullable;
 
 @AutoValue
@@ -29,36 +30,57 @@ public abstract class TransportContext {
   // For AbstractServiceStubClassComposer
   public abstract Transport transport();
 
+  @Nullable
   public abstract String transportName();
 
+  @Nullable
   public abstract Class<?> callSettingsClass();
 
+  @Nullable
   public abstract TypeNode stubCallableFactoryType();
 
+  @Nullable
   public abstract Class<?> methodDescriptorClass();
 
-  @Nullable
-  public abstract TypeNode transportOperationsStubType();
+  public abstract List<TypeNode> transportOperationsStubTypes();
+
+  public abstract List<String> transportOperationsStubNames();
 
   // For AbstractServiceSettingsClassComposer
-  public abstract Class<?> instantiatingChannelProviderClass();
+  public abstract List<Class<?>> instantiatingChannelProviderClasses();
 
-  public abstract String defaultTransportProviderBuilderName();
+  public abstract List<Class<?>> instantiatingChannelProviderBuilderClasses();
+
+  public abstract List<String> defaultTransportProviderBuilderNames();
+
+  public abstract List<String> transportApiClientHeaderProviderBuilderNames();
 
   // For AbstractServiceStubSettingsClassComposer
-  public abstract TypeNode transportChannelType();
+  public abstract List<TypeNode> transportChannelTypes();
 
-  public abstract String transportGetterName();
+  public abstract List<String> transportGetterNames();
 
   // For AbstractServiceCallableFactoryClassComposer
+  @Nullable
   public abstract TypeNode transportCallSettingsType();
 
+  @Nullable
   public abstract TypeNode transportCallableFactoryType();
 
-  public abstract TypeNode operationsStubType();
+  public abstract List<TypeNode> operationsStubTypes();
 
+  @Nullable
   public abstract String transportCallSettingsName();
 
+  // For RetrySettingsComposer
+  public abstract TypeNode operationResponseTransformerType();
+
+  public abstract TypeNode operationMetadataTransformerType();
+
+  public abstract List<TypeNode> operationsClientTypes();
+
+  public abstract List<String> operationsClientNames();
+
   protected static TypeNode classToType(Class<?> clazz) {
     return TypeNode.withReference(ConcreteReference.withClazz(clazz));
   }
@@ -82,15 +104,21 @@ public abstract static class Builder {
 
     public abstract Builder setMethodDescriptorClass(Class<?> methodDescriptorClass);
 
-    public abstract Builder setInstantiatingChannelProviderClass(
-        Class<?> instantiatingChannelProviderClass);
+    public abstract Builder setInstantiatingChannelProviderClasses(
+        List<Class<?>> instantiatingChannelProviderClasses);
+
+    public abstract Builder setInstantiatingChannelProviderBuilderClasses(
+        List<Class<?>> instantiatingChannelProviderBuilderClasses);
+
+    public abstract Builder setDefaultTransportProviderBuilderNames(
+        List<String> defaultTransportProviderBuilderNames);
 
-    public abstract Builder setDefaultTransportProviderBuilderName(
-        String defaultTransportProviderBuilderName);
+    public abstract Builder setTransportApiClientHeaderProviderBuilderNames(
+        List<String> transportApiClientHeaderProviderBuilderNames);
 
-    public abstract Builder setTransportChannelType(TypeNode transportChannelType);
+    public abstract Builder setTransportChannelTypes(List<TypeNode> transportChannelTypes);
 
-    public abstract Builder setTransportGetterName(String transportGetterName);
+    public abstract Builder setTransportGetterNames(List<String> transportGetterNames);
 
     public abstract Builder setTransportCallSettingsType(TypeNode transportCallSettingsType);
 
@@ -98,9 +126,19 @@ public abstract Builder setDefaultTransportProviderBuilderName(
 
     public abstract Builder setTransportCallSettingsName(String transportCallSettingsName);
 
-    public abstract Builder setTransportOperationsStubType(TypeNode transportOperationsStubType);
+    public abstract Builder setTransportOperationsStubTypes(List<TypeNode> transportOperationsStubTypes);
+
+    public abstract Builder setTransportOperationsStubNames(List<String> transportOperationsStubNames);
+
+    public abstract Builder setOperationsStubTypes(List<TypeNode> operationsStubType);
+
+    public abstract Builder setOperationResponseTransformerType(TypeNode operationResponseTransformerType);
+
+    public abstract Builder setOperationMetadataTransformerType(TypeNode operationMetadataTransformerType);
+
+    public abstract Builder setOperationsClientTypes(List<TypeNode> operationsClientTypes);
 
-    public abstract Builder setOperationsStubType(TypeNode operationsStubType);
+    public abstract Builder setOperationsClientNames(List<String> operationsClientNames);
 
     public abstract TransportContext build();
   }
diff --git a/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/BUILD.bazel b/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/BUILD.bazel
index 178459f813..48171ec5d3 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/BUILD.bazel
+++ b/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/BUILD.bazel
@@ -17,6 +17,7 @@ java_library(
         "//src/main/java/com/google/api/generator/gapic/composer/resourcename",
         "//src/main/java/com/google/api/generator/gapic/model",
         "//src/main/java/com/google/api/generator/gapic/utils",
+        "@com_google_api_api_common",
         "@com_google_googleapis//google/longrunning:longrunning_java_proto",
         "@com_google_guava_guava//jar",
         "@com_google_protobuf//java/core",
diff --git a/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposer.java b/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposer.java
index fec4d3050f..f697c1b4a2 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposer.java
@@ -14,11 +14,16 @@
 
 package com.google.api.generator.gapic.composer.defaultvalue;
 
+import com.google.api.generator.engine.ast.AnonymousClassExpr;
+import com.google.api.generator.engine.ast.AssignmentExpr;
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.Expr;
+import com.google.api.generator.engine.ast.ExprStatement;
+import com.google.api.generator.engine.ast.MethodDefinition;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
 import com.google.api.generator.engine.ast.NewObjectExpr;
 import com.google.api.generator.engine.ast.PrimitiveValue;
+import com.google.api.generator.engine.ast.ScopeNode;
 import com.google.api.generator.engine.ast.StringObjectValue;
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.ValueExpr;
@@ -31,12 +36,13 @@
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.api.generator.gapic.utils.ResourceNameConstants;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.longrunning.Operation;
 import com.google.protobuf.Any;
-import com.google.protobuf.ByteString;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -47,12 +53,13 @@ public class DefaultValueComposer {
   private static TypeNode OPERATION_TYPE =
       TypeNode.withReference(ConcreteReference.withClazz(Operation.class));
   private static TypeNode ANY_TYPE = TypeNode.withReference(ConcreteReference.withClazz(Any.class));
-  private static TypeNode BYTESTRING_TYPE =
-      TypeNode.withReference(ConcreteReference.withClazz(ByteString.class));
 
   public static Expr createDefaultValue(
-      MethodArgument methodArg, Map<String, ResourceName> resourceNames) {
-    if (methodArg.isResourceNameHelper()) {
+      MethodArgument methodArg,
+      Map<String, ResourceName> resourceNames,
+      boolean forceResourceNameInitializer) {
+    if (methodArg.isResourceNameHelper()
+        || (forceResourceNameInitializer && methodArg.field().hasResourceReference())) {
       Preconditions.checkState(
           methodArg.field().hasResourceReference(),
           String.format(
@@ -65,10 +72,21 @@ public static Expr createDefaultValue(
           String.format(
               "No resource name found for reference %s",
               methodArg.field().resourceReference().resourceTypeString()));
-      return createDefaultValue(
-          resourceName,
-          resourceNames.values().stream().collect(Collectors.toList()),
-          methodArg.field().name());
+      Expr defValue =
+          createDefaultValue(
+              resourceName,
+              resourceNames.values().stream().collect(Collectors.toList()),
+              methodArg.field().name());
+
+      if (!methodArg.isResourceNameHelper() && methodArg.field().hasResourceReference()) {
+        defValue =
+            MethodInvocationExpr.builder()
+                .setExprReferenceExpr(defValue)
+                .setMethodName("toString")
+                .setReturnType(TypeNode.STRING)
+                .build();
+      }
+      return defValue;
     }
 
     if (methodArg.type().equals(methodArg.field().type())) {
@@ -157,6 +175,16 @@ static Expr createDefaultValue(Field f, boolean useExplicitInitTypeInGenerics) {
 
   public static Expr createDefaultValue(
       ResourceName resourceName, List<ResourceName> resnames, String fieldOrMessageName) {
+    return createDefaultValueResourceHelper(resourceName, resnames, fieldOrMessageName, true);
+  }
+
+  @VisibleForTesting
+  static Expr createDefaultValueResourceHelper(
+      ResourceName resourceName,
+      List<ResourceName> resnames,
+      String fieldOrMessageName,
+      boolean allowAnonResourceNameClass) {
+
     boolean hasOnePattern = resourceName.patterns().size() == 1;
     if (resourceName.isOnlyWildcard()) {
       List<ResourceName> unexaminedResnames = new ArrayList<>(resnames);
@@ -170,9 +198,11 @@ public static Expr createDefaultValue(
       }
 
       if (unexaminedResnames.isEmpty()) {
-        return ValueExpr.withValue(
-            StringObjectValue.withValue(
-                String.format("%s%s", fieldOrMessageName, fieldOrMessageName.hashCode())));
+        return allowAnonResourceNameClass
+            ? createAnonymousResourceNameClass(fieldOrMessageName)
+            : ValueExpr.withValue(
+                StringObjectValue.withValue(
+                    String.format("%s%s", fieldOrMessageName, fieldOrMessageName.hashCode())));
       }
     }
 
@@ -247,10 +277,11 @@ public static Expr createSimpleMessageBuilderExpr(
       if (field.hasResourceReference()
           && resourceNames.get(field.resourceReference().resourceTypeString()) != null) {
         defaultExpr =
-            createDefaultValue(
+            createDefaultValueResourceHelper(
                 resourceNames.get(field.resourceReference().resourceTypeString()),
                 resourceNames.values().stream().collect(Collectors.toList()),
-                message.name());
+                message.name(),
+                /* allowAnonResourceNameClass = */ false);
         defaultExpr =
             MethodInvocationExpr.builder()
                 .setExprReferenceExpr(defaultExpr)
@@ -315,7 +346,19 @@ public static Expr createSimpleOperationBuilderExpr(String name, VariableExpr re
   }
 
   public static Expr createSimplePagedResponse(
-      TypeNode responseType, String repeatedFieldName, Expr responseElementVarExpr) {
+      TypeNode responseType, String repeatedFieldName, Expr responseElementVarExpr, boolean isMap) {
+    // Code for paginated maps:
+    // AggregatedMessageList.newBuilder()
+    //     .setNextPageToken("")
+    //     .putAllItems(Collections.singletonMap("items", responsesElement))
+    //     .build();
+    //
+    // Code for paginated arrays:
+    // MessageList expectedResponse =
+    //     AddressList.newBuilder()
+    //         .setNextPageToken("")
+    //         .addAllItems(Arrays.asList(responsesElement))
+    //         .build();
     Expr pagedResponseExpr =
         MethodInvocationExpr.builder()
             .setStaticReferenceType(responseType)
@@ -327,22 +370,131 @@ public static Expr createSimplePagedResponse(
             .setMethodName("setNextPageToken")
             .setArguments(ValueExpr.withValue(StringObjectValue.withValue("")))
             .build();
-    pagedResponseExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(pagedResponseExpr)
-            .setMethodName(String.format("addAll%s", JavaStyle.toUpperCamelCase(repeatedFieldName)))
-            .setArguments(
-                MethodInvocationExpr.builder()
-                    .setStaticReferenceType(
-                        TypeNode.withReference(ConcreteReference.withClazz(Arrays.class)))
-                    .setMethodName("asList")
-                    .setArguments(responseElementVarExpr)
-                    .build())
-            .build();
+    if (isMap) {
+      pagedResponseExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(pagedResponseExpr)
+              .setMethodName(
+                  String.format("putAll%s", JavaStyle.toUpperCamelCase(repeatedFieldName)))
+              .setArguments(
+                  MethodInvocationExpr.builder()
+                      .setStaticReferenceType(
+                          TypeNode.withReference(ConcreteReference.withClazz(Collections.class)))
+                      .setMethodName("singletonMap")
+                      .setArguments(
+                          ValueExpr.withValue(
+                              StringObjectValue.withValue(
+                                  JavaStyle.toLowerCamelCase(repeatedFieldName))),
+                          responseElementVarExpr)
+                      .build())
+              .build();
+    } else {
+      pagedResponseExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(pagedResponseExpr)
+              .setMethodName(
+                  String.format("addAll%s", JavaStyle.toUpperCamelCase(repeatedFieldName)))
+              .setArguments(
+                  MethodInvocationExpr.builder()
+                      .setStaticReferenceType(
+                          TypeNode.withReference(ConcreteReference.withClazz(Arrays.class)))
+                      .setMethodName("asList")
+                      .setArguments(responseElementVarExpr)
+                      .build())
+              .build();
+    }
     return MethodInvocationExpr.builder()
         .setExprReferenceExpr(pagedResponseExpr)
         .setMethodName("build")
         .setReturnType(responseType)
         .build();
   }
+
+  @VisibleForTesting
+  static AnonymousClassExpr createAnonymousResourceNameClass(String fieldOrMessageName) {
+    TypeNode stringMapType =
+        TypeNode.withReference(
+            ConcreteReference.builder()
+                .setClazz(Map.class)
+                .setGenerics(
+                    Arrays.asList(
+                        ConcreteReference.withClazz(String.class),
+                        ConcreteReference.withClazz(String.class)))
+                .build());
+
+    // Method code:
+    // @Override
+    // public Map<String, String> getFieldValuesMap() {
+    //   Map<String, String> fieldValuesMap = new HashMap<>();
+    //   fieldValuesMap.put("resource", "resource-12345");
+    //   return fieldValuesMap;
+    // }
+    VariableExpr fieldValuesMapVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setType(stringMapType).setName("fieldValuesMap").build());
+    StringObjectValue fieldOrMessageStringValue =
+        StringObjectValue.withValue(
+            String.format("%s%s", fieldOrMessageName, fieldOrMessageName.hashCode()));
+
+    List<Expr> bodyExprs =
+        Arrays.asList(
+            AssignmentExpr.builder()
+                .setVariableExpr(fieldValuesMapVarExpr.toBuilder().setIsDecl(true).build())
+                .setValueExpr(
+                    NewObjectExpr.builder()
+                        .setType(TypeNode.withReference(ConcreteReference.withClazz(HashMap.class)))
+                        .setIsGeneric(true)
+                        .build())
+                .build(),
+            MethodInvocationExpr.builder()
+                .setExprReferenceExpr(fieldValuesMapVarExpr)
+                .setMethodName("put")
+                .setArguments(
+                    ValueExpr.withValue(StringObjectValue.withValue(fieldOrMessageName)),
+                    ValueExpr.withValue(fieldOrMessageStringValue))
+                .build());
+
+    MethodDefinition getFieldValuesMapMethod =
+        MethodDefinition.builder()
+            .setIsOverride(true)
+            .setScope(ScopeNode.PUBLIC)
+            .setReturnType(stringMapType)
+            .setName("getFieldValuesMap")
+            .setBody(
+                bodyExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()))
+            .setReturnExpr(fieldValuesMapVarExpr)
+            .build();
+
+    // Method code:
+    // @Override
+    // public String getFieldValue(String fieldName) {
+    //   return getFieldValuesMap().get(fieldName);
+    // }
+    VariableExpr fieldNameVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setType(TypeNode.STRING).setName("fieldName").build());
+    MethodDefinition getFieldValueMethod =
+        MethodDefinition.builder()
+            .setIsOverride(true)
+            .setScope(ScopeNode.PUBLIC)
+            .setReturnType(TypeNode.STRING)
+            .setName("getFieldValue")
+            .setArguments(fieldNameVarExpr.toBuilder().setIsDecl(true).build())
+            .setReturnExpr(
+                MethodInvocationExpr.builder()
+                    .setExprReferenceExpr(
+                        MethodInvocationExpr.builder().setMethodName("getFieldValuesMap").build())
+                    .setMethodName("get")
+                    .setArguments(fieldNameVarExpr)
+                    .setReturnType(TypeNode.STRING)
+                    .build())
+            .build();
+
+    return AnonymousClassExpr.builder()
+        .setType(
+            TypeNode.withReference(
+                ConcreteReference.withClazz(com.google.api.resourcenames.ResourceName.class)))
+        .setMethods(Arrays.asList(getFieldValuesMapMethod, getFieldValueMethod))
+        .build();
+  }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcContext.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcContext.java
index 13623cfb5b..5f9b27963e 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcContext.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcContext.java
@@ -19,9 +19,12 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.grpc.GrpcTransportChannel;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.grpc.ProtoOperationTransformers;
+import com.google.api.generator.gapic.composer.common.TransportContext;
 import com.google.api.generator.gapic.composer.utils.ClassNames;
 import com.google.api.generator.gapic.model.Transport;
-import com.google.api.generator.gapic.composer.common.TransportContext;
+import com.google.common.collect.ImmutableList;
+import com.google.longrunning.OperationsClient;
 import com.google.longrunning.stub.GrpcOperationsStub;
 import com.google.longrunning.stub.OperationsStub;
 import io.grpc.MethodDescriptor;
@@ -36,18 +39,33 @@ public abstract class GrpcContext extends TransportContext {
           .setCallSettingsClass(GrpcCallSettings.class)
           .setStubCallableFactoryType(classToType(GrpcStubCallableFactory.class))
           .setMethodDescriptorClass(MethodDescriptor.class)
-          .setTransportOperationsStubType(classToType(GrpcOperationsStub.class))
+          .setTransportOperationsStubTypes(ImmutableList.of(classToType(GrpcOperationsStub.class)))
+          .setTransportOperationsStubNames(ImmutableList.of("operationsStub"))
           // For grpc.ServiceSettingsClassComposer
-          .setInstantiatingChannelProviderClass(InstantiatingGrpcChannelProvider.Builder.class)
-          .setDefaultTransportProviderBuilderName("defaultGrpcTransportProviderBuilder")
+          .setInstantiatingChannelProviderClasses(
+              ImmutableList.of(InstantiatingGrpcChannelProvider.class))
+          .setInstantiatingChannelProviderBuilderClasses(
+              ImmutableList.of(InstantiatingGrpcChannelProvider.Builder.class))
+          .setDefaultTransportProviderBuilderNames(
+              ImmutableList.of("defaultGrpcTransportProviderBuilder"))
+          .setTransportApiClientHeaderProviderBuilderNames(
+              ImmutableList.of("defaultGrpcApiClientHeaderProviderBuilder"))
           // For grpc.ServiceStubSettingsClassComposer
-          .setTransportChannelType(classToType(GrpcTransportChannel.class))
-          .setTransportGetterName("getGrpcTransportName")
+          .setTransportChannelTypes(ImmutableList.of(classToType(GrpcTransportChannel.class)))
+          .setTransportGetterNames(ImmutableList.of("getGrpcTransportName"))
           // For grpc.GrpcServiceCallableFactoryClassComposer
           .setTransportCallSettingsType(classToType(GrpcCallSettings.class))
           .setTransportCallableFactoryType(classToType(GrpcCallableFactory.class))
-          .setOperationsStubType(classToType(OperationsStub.class))
+          .setOperationsStubTypes(ImmutableList.of(classToType(OperationsStub.class)))
           .setTransportCallSettingsName("grpcCallSettings")
+          // For RetrySettingsComposer
+          .setOperationResponseTransformerType(
+              classToType(ProtoOperationTransformers.ResponseTransformer.class))
+          .setOperationMetadataTransformerType(
+              classToType(ProtoOperationTransformers.MetadataTransformer.class))
+          // For ServiceClientClassComposer
+          .setOperationsClientTypes(ImmutableList.of(classToType(OperationsClient.class)))
+          .setOperationsClientNames(ImmutableList.of("operationsClient"))
           .build();
 
   public static TransportContext instance() {
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceCallableFactoryClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceCallableFactoryClassComposer.java
index 5698f5a443..e953c1410a 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceCallableFactoryClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceCallableFactoryClassComposer.java
@@ -45,6 +45,7 @@ protected List<TypeNode> createClassImplements(TypeStore typeStore) {
     return Arrays.asList(getTransportContext().stubCallableFactoryType());
   }
 
+  @Override
   protected List<MethodDefinition> createClassMethods(TypeStore typeStore) {
     List<MethodDefinition> classMethods = new ArrayList<>(super.createClassMethods(typeStore));
     classMethods.addAll(
@@ -55,6 +56,7 @@ protected List<MethodDefinition> createClassMethods(TypeStore typeStore) {
     return classMethods;
   }
 
+  @Override
   protected MethodDefinition createUnaryCallableMethod(TypeStore typeStore) {
     String methodVariantName = "Unary";
     String requestTemplateName = "RequestT";
@@ -75,6 +77,7 @@ protected MethodDefinition createUnaryCallableMethod(TypeStore typeStore) {
             .collect(Collectors.toList()));
   }
 
+  @Override
   protected MethodDefinition createPagedCallableMethod(TypeStore typeStore) {
     String methodVariantName = "Paged";
     String requestTemplateName = "RequestT";
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposer.java
index e7b30ebcbe..578ce02005 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposer.java
@@ -16,14 +16,12 @@
 
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
-import com.google.api.gax.rpc.RequestParamsExtractor;
-import com.google.api.generator.engine.ast.AnonymousClassExpr;
 import com.google.api.generator.engine.ast.AssignmentExpr;
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.EnumRefExpr;
 import com.google.api.generator.engine.ast.Expr;
 import com.google.api.generator.engine.ast.ExprStatement;
-import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.LambdaExpr;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
 import com.google.api.generator.engine.ast.ScopeNode;
 import com.google.api.generator.engine.ast.Statement;
@@ -32,10 +30,9 @@
 import com.google.api.generator.engine.ast.ValueExpr;
 import com.google.api.generator.engine.ast.Variable;
 import com.google.api.generator.engine.ast.VariableExpr;
-import com.google.api.generator.gapic.composer.common.AbstractServiceStubClassComposer;
-import com.google.api.generator.gapic.composer.comment.StubCommentComposer;
+import com.google.api.generator.gapic.composer.common.AbstractTransportServiceStubClassComposer;
 import com.google.api.generator.gapic.composer.store.TypeStore;
-import com.google.api.generator.gapic.composer.utils.ClassNames;
+import com.google.api.generator.gapic.model.HttpBindings.HttpBinding;
 import com.google.api.generator.gapic.model.Method;
 import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.utils.JavaStyle;
@@ -54,7 +51,7 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-public class GrpcServiceStubClassComposer extends AbstractServiceStubClassComposer {
+public class GrpcServiceStubClassComposer extends AbstractTransportServiceStubClassComposer {
   private static final GrpcServiceStubClassComposer INSTANCE = new GrpcServiceStubClassComposer();
 
   // Legacy support for the original reroute_to_grpc_interface option in gapic.yaml. These two APIs
@@ -75,7 +72,7 @@ public static GrpcServiceStubClassComposer instance() {
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             GrpcCallSettings.class,
             GrpcOperationsStub.class,
@@ -155,7 +152,8 @@ protected Statement createMethodDescriptorVariableDecl(
     return ExprStatement.withExpr(
         AssignmentExpr.builder()
             .setVariableExpr(
-                methodDescriptorVarExpr.toBuilder()
+                methodDescriptorVarExpr
+                    .toBuilder()
                     .setIsDecl(true)
                     .setScope(ScopeNode.PRIVATE)
                     .setIsStatic(true)
@@ -190,18 +188,6 @@ protected EnumRefExpr getMethodDescriptorMethodTypeExpr(Method protoMethod) {
         .build();
   }
 
-  @Override
-  protected List<MethodDefinition> createOperationsStubGetterMethod(
-      VariableExpr operationsStubVarExpr) {
-    return Arrays.asList(
-        MethodDefinition.builder()
-            .setScope(ScopeNode.PUBLIC)
-            .setReturnType(operationsStubVarExpr.type())
-            .setName("getOperationsStub")
-            .setReturnExpr(operationsStubVarExpr)
-            .build());
-  }
-
   @Override
   protected Expr createTransportSettingsInitExpr(
       Method method, VariableExpr transportSettingsVarExpr, VariableExpr methodDescriptorVarExpr) {
@@ -223,7 +209,7 @@ protected Expr createTransportSettingsInitExpr(
           MethodInvocationExpr.builder()
               .setExprReferenceExpr(callSettingsBuilderExpr)
               .setMethodName("setParamsExtractor")
-              .setArguments(createRequestParamsExtractorAnonClass(method))
+              .setArguments(createRequestParamsExtractorClassInstance(method))
               .build();
     }
 
@@ -255,7 +241,7 @@ protected String getProtoRpcFullMethodName(Service protoService, Method protoMet
     return String.format("google.iam.v1.IAMPolicy/%s", protoMethod.name());
   }
 
-  private AnonymousClassExpr createRequestParamsExtractorAnonClass(Method method) {
+  private LambdaExpr createRequestParamsExtractorClassInstance(Method method) {
     Preconditions.checkState(
         method.hasHttpBindings(), String.format("Method %s has no HTTP binding", method.name()));
 
@@ -268,9 +254,6 @@ private AnonymousClassExpr createRequestParamsExtractorAnonClass(Method method)
     VariableExpr paramsVarExpr =
         VariableExpr.withVariable(
             Variable.builder().setName("params").setType(paramsVarType).build());
-    VariableExpr reqeustVarExpr =
-        VariableExpr.withVariable(
-            Variable.builder().setName("request").setType(method.inputType()).build());
 
     Expr paramsAssignExpr =
         AssignmentExpr.builder()
@@ -289,11 +272,11 @@ private AnonymousClassExpr createRequestParamsExtractorAnonClass(Method method)
         VariableExpr.withVariable(
             Variable.builder().setType(method.inputType()).setName("request").build());
 
-    for (String httpBindingFieldName : method.httpBindings()) {
+    for (HttpBinding httpBindingFieldBinding : method.httpBindings().pathParameters()) {
       // Handle foo.bar cases by descending into the subfields.
       MethodInvocationExpr.Builder requestFieldGetterExprBuilder =
           MethodInvocationExpr.builder().setExprReferenceExpr(requestVarExpr);
-      String[] descendantFields = httpBindingFieldName.split("\\.");
+      String[] descendantFields = httpBindingFieldBinding.name().split("\\.");
       for (int i = 0; i < descendantFields.length; i++) {
         String currFieldName = descendantFields[i];
         String bindingFieldMethodName =
@@ -320,7 +303,7 @@ private AnonymousClassExpr createRequestParamsExtractorAnonClass(Method method)
               .setExprReferenceExpr(paramsVarExpr)
               .setMethodName("put")
               .setArguments(
-                  ValueExpr.withValue(StringObjectValue.withValue(httpBindingFieldName)),
+                  ValueExpr.withValue(StringObjectValue.withValue(httpBindingFieldBinding.name())),
                   valueOfExpr)
               .build();
       bodyExprs.add(paramsPutExpr);
@@ -339,24 +322,13 @@ private AnonymousClassExpr createRequestParamsExtractorAnonClass(Method method)
             .setReturnType(returnType)
             .build();
 
-    MethodDefinition extractMethod =
-        MethodDefinition.builder()
-            .setIsOverride(true)
-            .setScope(ScopeNode.PUBLIC)
-            .setReturnType(returnType)
-            .setName("extract")
-            .setArguments(requestVarExpr.toBuilder().setIsDecl(true).build())
-            .setBody(
-                bodyExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()))
-            .setReturnExpr(returnExpr)
-            .build();
-
-    TypeNode anonClassType =
-        TypeNode.withReference(
-            ConcreteReference.builder()
-                .setClazz(RequestParamsExtractor.class)
-                .setGenerics(method.inputType().reference())
-                .build());
-    return AnonymousClassExpr.builder().setType(anonClassType).setMethods(extractMethod).build();
+    // Overrides extract().
+    // https://github.com/googleapis/gax-java/blob/8d45d186e36ae97b789a6f89d80ae5213a773b65/gax/src/main/java/com/google/api/gax/rpc/RequestParamsExtractor.java#L55
+    return LambdaExpr.builder()
+        .setArguments(requestVarExpr.toBuilder().setIsDecl(true).build())
+        .setBody(
+            bodyExprs.stream().map(e -> ExprStatement.withExpr(e)).collect(Collectors.toList()))
+        .setReturnExpr(returnExpr)
+        .build();
   }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceClassComposer.java
index f1ac25fd06..7227b4fe4a 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceClassComposer.java
@@ -234,7 +234,7 @@ private static MethodDefinition createResetMethod(VariableExpr serviceImplVarExp
   }
 
   private static TypeStore createTypes(Service service) {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             AbstractMessage.class, BetaApi.class, Generated.class, ServerServiceDefinition.class);
     TypeStore typeStore = new TypeStore(concreteClazzes);
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceImplClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceImplClassComposer.java
index a58601197d..e16cc875f4 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceImplClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/MockServiceImplClassComposer.java
@@ -28,6 +28,7 @@
 import com.google.api.generator.engine.ast.MethodDefinition;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
 import com.google.api.generator.engine.ast.NewObjectExpr;
+import com.google.api.generator.engine.ast.Reference;
 import com.google.api.generator.engine.ast.RelationalOperationExpr;
 import com.google.api.generator.engine.ast.ScopeNode;
 import com.google.api.generator.engine.ast.Statement;
@@ -78,17 +79,9 @@ public class MockServiceImplClassComposer implements ClassComposer {
                               Arrays.asList(FIXED_TYPESTORE.get("AbstractMessage").reference()))
                           .build()))
               .build());
-  private static final VariableExpr responsesVarExpr =
-      VariableExpr.withVariable(
-          Variable.builder()
-              .setName("responses")
-              .setType(
-                  TypeNode.withReference(
-                      ConcreteReference.builder()
-                          .setClazz(Queue.class)
-                          .setGenerics(Arrays.asList(ConcreteReference.withClazz(Object.class)))
-                          .build()))
-              .build());
+
+  private static Reference javaObjectReference = ConcreteReference.withClazz(Object.class);
+  private static VariableExpr responsesVarExpr;
 
   private MockServiceImplClassComposer() {}
 
@@ -97,12 +90,32 @@ public static MockServiceImplClassComposer instance() {
   }
 
   @Override
-  public GapicClass generate(GapicContext ignored, Service service) {
+  public GapicClass generate(GapicContext context, Service service) {
     TypeStore typeStore = createDynamicTypes(service);
     String className = ClassNames.getMockServiceImplClassName(service);
     GapicClass.Kind kind = Kind.TEST;
     String pakkage = service.pakkage();
 
+    // Use the full name java.lang.Object if there is a proto message that is also named "Object".
+    // Affects GCS.
+    if (context.messages().keySet().stream()
+        .anyMatch(s -> s.equals("Object") || s.endsWith(".Object"))) {
+      javaObjectReference =
+          ConcreteReference.builder().setClazz(Object.class).setUseFullName(true).build();
+    }
+
+    responsesVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setName("responses")
+                .setType(
+                    TypeNode.withReference(
+                        ConcreteReference.builder()
+                            .setClazz(Queue.class)
+                            .setGenerics(Arrays.asList(javaObjectReference))
+                            .build()))
+                .build());
+
     ClassDefinition classDef =
         ClassDefinition.builder()
             .setPackageString(pakkage)
@@ -212,8 +225,7 @@ private static MethodDefinition createSetResponsesMethod(Service service) {
                         TypeNode.withReference(
                             ConcreteReference.builder()
                                 .setClazz(LinkedList.class)
-                                .setGenerics(
-                                    Arrays.asList(ConcreteReference.withClazz(Object.class)))
+                                .setGenerics(Arrays.asList(javaObjectReference))
                                 .build()))
                     .setArguments(Arrays.asList(responsesArgVarExpr))
                     .build())
@@ -267,7 +279,7 @@ private static List<MethodDefinition> createProtoMethodOverrides(Service service
 
   private static MethodDefinition createGenericProtoMethodOverride(Method protoMethod) {
     ConcreteReference streamObserverRef = ConcreteReference.withClazz(StreamObserver.class);
-    TypeNode objectType = TypeNode.withReference(ConcreteReference.withClazz(Object.class));
+    TypeNode objectType = TypeNode.withReference(javaObjectReference);
     VariableExpr localResponseVarExpr =
         VariableExpr.withVariable(
             Variable.builder().setName("response").setType(objectType).build());
@@ -342,7 +354,7 @@ private static MethodDefinition createGenericClientStreamingProtoMethodOverride(
                     AssignmentExpr.builder()
                         .setVariableExpr(requestObserverVarExpr.toBuilder().setIsDecl(true).build())
                         .setValueExpr(
-                            createStreamObserverAnonymousClassExpr(
+                            createStreamObserverClassInstance(
                                 protoMethod,
                                 returnType,
                                 responseObserverVarExpr,
@@ -352,7 +364,7 @@ private static MethodDefinition createGenericClientStreamingProtoMethodOverride(
         .build();
   }
 
-  private static AnonymousClassExpr createStreamObserverAnonymousClassExpr(
+  private static AnonymousClassExpr createStreamObserverClassInstance(
       Method protoMethod,
       TypeNode classType,
       VariableExpr responseObserverVarExpr,
@@ -372,7 +384,7 @@ private static MethodDefinition createOnNextJavaMethod(
     VariableExpr valueVarExpr =
         VariableExpr.withVariable(
             Variable.builder().setName("value").setType(protoMethod.inputType()).build());
-    TypeNode objectType = TypeNode.withReference(ConcreteReference.withClazz(Object.class));
+    TypeNode objectType = TypeNode.withReference(javaObjectReference);
 
     Statement addValueToRequestsStatement =
         ExprStatement.withExpr(
@@ -584,7 +596,7 @@ private static Statement createHandleObjectStatement(
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             AbstractMessage.class,
             ArrayList.class,
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientClassComposer.java
new file mode 100644
index 0000000000..9b95e9c280
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientClassComposer.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.api.generator.gapic.composer.grpc;
+
+import com.google.api.generator.gapic.composer.common.AbstractServiceClientClassComposer;
+
+public class ServiceClientClassComposer extends AbstractServiceClientClassComposer {
+  private static final ServiceClientClassComposer INSTANCE = new ServiceClientClassComposer();
+
+  protected ServiceClientClassComposer() {
+    super(GrpcContext.instance());
+  }
+
+  public static ServiceClientClassComposer instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposer.java
index 8d06bd29a9..8cb761236a 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposer.java
@@ -53,14 +53,13 @@
 import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
 import com.google.protobuf.AbstractMessage;
 import io.grpc.StatusRuntimeException;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.concurrent.ExecutionException;
 import java.util.function.BiFunction;
 import java.util.function.Function;
@@ -73,7 +72,7 @@ public class ServiceClientTestClassComposer extends AbstractServiceClientTestCla
   private static final ServiceClientTestClassComposer INSTANCE =
       new ServiceClientTestClassComposer();
 
-  protected static final TypeStore FIXED_GRPC_TYPESTORE = createStaticTypes();
+  private static final TypeStore FIXED_GRPC_TYPESTORE = createStaticTypes();
 
   private static final TypeNode LIST_TYPE =
       TypeNode.withReference(ConcreteReference.withClazz(List.class));
@@ -97,7 +96,7 @@ public static AbstractServiceClientTestClassComposer instance() {
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             GaxGrpcProperties.class,
             LocalChannelProvider.class,
@@ -115,7 +114,8 @@ protected Map<String, VariableExpr> createClassMemberVarExprs(
     BiFunction<String, TypeNode, VariableExpr> varExprFn =
         (name, type) ->
             VariableExpr.withVariable(Variable.builder().setName(name).setType(type).build());
-    Map<String, TypeNode> fields = new LinkedHashMap<>();
+    // Keep keys sorted in alphabetical order to ensure that the test output is deterministic.
+    Map<String, TypeNode> fields = new TreeMap<>();
     fields.put(
         getMockServiceVarName(service), typeStore.get(ClassNames.getMockServiceClassName(service)));
     for (Service mixinService : context.mixinServices()) {
@@ -132,8 +132,10 @@ protected Map<String, VariableExpr> createClassMemberVarExprs(
             Collectors.toMap(
                 Map.Entry::getKey,
                 e -> varExprFn.apply(e.getKey(), e.getValue()),
-                (u, v) -> {throw new IllegalStateException();},
-                LinkedHashMap::new));
+                (u, v) -> {
+                  throw new IllegalStateException();
+                },
+                TreeMap::new));
   }
 
   @Override
@@ -141,7 +143,8 @@ protected MethodDefinition createStartStaticServerMethod(
       Service service,
       GapicContext context,
       Map<String, VariableExpr> classMemberVarExprs,
-      TypeStore typeStore) {
+      TypeStore typeStore,
+      String newBuilderMethod) {
     VariableExpr serviceHelperVarExpr = classMemberVarExprs.get(SERVICE_HELPER_VAR_NAME);
     Function<Service, VariableExpr> serviceToVarExprFn =
         s -> classMemberVarExprs.get(getMockServiceVarName(s));
@@ -157,7 +160,12 @@ protected MethodDefinition createStartStaticServerMethod(
     List<Expr> mockServiceVarExprs = new ArrayList<>();
     varInitExprs.add(serviceToVarInitExprFn.apply(service));
     mockServiceVarExprs.add(serviceToVarExprFn.apply(service));
-    for (Service mixinService : context.mixinServices()) {
+    // Careful: Java 8 and 11 make different ordering choices if this set is not explicitly sorted.
+    // Context: https://github.com/googleapis/gapic-generator-java/pull/750
+    for (Service mixinService :
+        context.mixinServices().stream()
+            .sorted((s1, s2) -> s2.name().compareTo(s1.name()))
+            .collect(Collectors.toList())) {
       varInitExprs.add(serviceToVarInitExprFn.apply(mixinService));
       mockServiceVarExprs.add(serviceToVarExprFn.apply(mixinService));
     }
@@ -1036,14 +1044,21 @@ protected List<Statement> createStreamingRpcExceptionTestStatements(
                 tryBodyExprs.stream()
                     .map(e -> ExprStatement.withExpr(e))
                     .collect(Collectors.toList()))
-            .setCatchVariableExpr(catchExceptionVarExpr.toBuilder().setIsDecl(true).build())
-            .setCatchBody(createRpcLroExceptionTestCatchBody(catchExceptionVarExpr, true))
+            .addCatch(
+                catchExceptionVarExpr.toBuilder().setIsDecl(true).build(),
+                createRpcLroExceptionTestCatchBody(catchExceptionVarExpr, true))
             .build();
 
     statements.add(tryCatchBlock);
     return statements;
   }
 
+  @Override
+  protected Expr createDefaultValue(
+      MethodArgument methodArg, Map<String, ResourceName> resourceNames) {
+    return DefaultValueComposer.createDefaultValue(methodArg, resourceNames, false);
+  }
+
   @Override
   protected List<Statement> createRpcLroExceptionTestCatchBody(
       VariableExpr exceptionExpr, boolean isStreaming) {
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceSettingsClassComposer.java
index 9d4c9bc294..ff0e4ed23f 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceSettingsClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceSettingsClassComposer.java
@@ -17,8 +17,7 @@
 import com.google.api.generator.gapic.composer.common.AbstractServiceSettingsClassComposer;
 
 public class ServiceSettingsClassComposer extends AbstractServiceSettingsClassComposer {
-  private static final ServiceSettingsClassComposer INSTANCE =
-      new ServiceSettingsClassComposer();
+  private static final ServiceSettingsClassComposer INSTANCE = new ServiceSettingsClassComposer();
 
   protected ServiceSettingsClassComposer() {
     super(GrpcContext.instance());
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubClassComposer.java
new file mode 100644
index 0000000000..1e11c5087d
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubClassComposer.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.api.generator.gapic.composer.grpc;
+
+import com.google.api.generator.gapic.composer.common.AbstractServiceStubClassComposer;
+
+public class ServiceStubClassComposer extends AbstractServiceStubClassComposer {
+  private static final ServiceStubClassComposer INSTANCE = new ServiceStubClassComposer();
+
+  protected ServiceStubClassComposer() {
+    super(GrpcContext.instance());
+  }
+
+  public static ServiceStubClassComposer instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposer.java
index 9d96aba607..a897f3003d 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposer.java
@@ -14,33 +14,33 @@
 
 package com.google.api.generator.gapic.composer.grpc;
 
+import com.google.api.gax.core.GoogleCredentialsProvider;
 import com.google.api.gax.grpc.GaxGrpcProperties;
 import com.google.api.gax.grpc.GrpcTransportChannel;
 import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.generator.engine.ast.AnnotationNode;
 import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.Expr;
 import com.google.api.generator.engine.ast.MethodDefinition;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.PrimitiveValue;
 import com.google.api.generator.engine.ast.ScopeNode;
-import com.google.api.generator.engine.ast.StringObjectValue;
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.ValueExpr;
 import com.google.api.generator.engine.ast.Variable;
 import com.google.api.generator.engine.ast.VariableExpr;
-import com.google.api.generator.gapic.composer.common.AbstractServiceStubSettingsClassComposer;
 import com.google.api.generator.gapic.composer.comment.SettingsCommentComposer;
+import com.google.api.generator.gapic.composer.common.AbstractServiceStubSettingsClassComposer;
 import com.google.api.generator.gapic.composer.store.TypeStore;
-import com.google.api.generator.gapic.composer.utils.ClassNames;
 import com.google.api.generator.gapic.model.Service;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 public class ServiceStubSettingsClassComposer extends AbstractServiceStubSettingsClassComposer {
   private static final ServiceStubSettingsClassComposer INSTANCE =
       new ServiceStubSettingsClassComposer();
 
-  protected static final TypeStore FIXED_GRPC_TYPESTORE = createStaticTypes();
+  private static final TypeStore FIXED_GRPC_TYPESTORE = createStaticTypes();
 
   public static ServiceStubSettingsClassComposer instance() {
     return INSTANCE;
@@ -51,7 +51,7 @@ protected ServiceStubSettingsClassComposer() {
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             GaxGrpcProperties.class,
             GrpcTransportChannel.class,
@@ -60,106 +60,74 @@ private static TypeStore createStaticTypes() {
   }
 
   @Override
-  protected MethodDefinition createDefaultTransportTransportProviderBuilderMethod() {
-    // Create the defaultGrpcTransportProviderBuilder method.
-    TypeNode returnType =
-        TypeNode.withReference(
-            ConcreteReference.withClazz(InstantiatingGrpcChannelProvider.Builder.class));
-    MethodInvocationExpr transportChannelProviderBuilderExpr =
-        MethodInvocationExpr.builder()
-            .setStaticReferenceType(
-                FIXED_GRPC_TYPESTORE.get(InstantiatingGrpcChannelProvider.class.getSimpleName()))
-            .setMethodName("newBuilder")
-            .build();
-    transportChannelProviderBuilderExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(transportChannelProviderBuilderExpr)
-            .setMethodName("setMaxInboundMessageSize")
-            .setArguments(
-                VariableExpr.builder()
-                    .setVariable(
-                        Variable.builder().setType(TypeNode.INT).setName("MAX_VALUE").build())
-                    .setStaticReferenceType(TypeNode.INT_OBJECT)
-                    .build())
-            .setReturnType(returnType)
-            .build();
-    return MethodDefinition.builder()
-        .setHeaderCommentStatements(
-            SettingsCommentComposer.DEFAULT_TRANSPORT_PROVIDER_BUILDER_METHOD_COMMENT)
-        .setScope(ScopeNode.PUBLIC)
-        .setIsStatic(true)
+  protected Expr initializeTransportProviderBuilder(
+      MethodInvocationExpr transportChannelProviderBuilderExpr, TypeNode returnType) {
+    return MethodInvocationExpr.builder()
+        .setExprReferenceExpr(transportChannelProviderBuilderExpr)
+        .setMethodName("setMaxInboundMessageSize")
+        .setArguments(
+            VariableExpr.builder()
+                .setVariable(Variable.builder().setType(TypeNode.INT).setName("MAX_VALUE").build())
+                .setStaticReferenceType(TypeNode.INT_OBJECT)
+                .build())
         .setReturnType(returnType)
-        .setName("defaultGrpcTransportProviderBuilder")
-        .setReturnExpr(transportChannelProviderBuilderExpr)
         .build();
   }
 
   @Override
-  protected MethodDefinition createDefaultApiClientHeaderProviderBuilderMethod(
-      Service service, TypeStore typeStore) {
-    // Create the defaultApiClientHeaderProviderBuilder method.
+  protected MethodDefinition createDefaultCredentialsProviderBuilderMethod() {
     TypeNode returnType =
-        TypeNode.withReference(ConcreteReference.withClazz(ApiClientHeaderProvider.Builder.class));
-    MethodInvocationExpr returnExpr =
+        TypeNode.withReference(
+            ConcreteReference.withClazz(GoogleCredentialsProvider.Builder.class));
+    MethodInvocationExpr credsProviderBuilderExpr =
         MethodInvocationExpr.builder()
-            .setStaticReferenceType(FIXED_TYPESTORE.get("ApiClientHeaderProvider"))
+            .setStaticReferenceType(FIXED_TYPESTORE.get("GoogleCredentialsProvider"))
             .setMethodName("newBuilder")
             .build();
-
-    MethodInvocationExpr versionArgExpr =
+    credsProviderBuilderExpr =
         MethodInvocationExpr.builder()
-            .setStaticReferenceType(FIXED_TYPESTORE.get("GaxProperties"))
-            .setMethodName("getLibraryVersion")
-            .setArguments(
-                VariableExpr.builder()
-                    .setVariable(
-                        Variable.builder().setType(TypeNode.CLASS_OBJECT).setName("class").build())
-                    .setStaticReferenceType(
-                        typeStore.get(ClassNames.getServiceStubSettingsClassName(service)))
-                    .build())
+            .setExprReferenceExpr(credsProviderBuilderExpr)
+            .setMethodName("setScopesToApply")
+            .setArguments(DEFAULT_SERVICE_SCOPES_VAR_EXPR)
+            .setReturnType(returnType)
             .build();
 
-    returnExpr =
-        MethodInvocationExpr.builder()
-            .setExprReferenceExpr(returnExpr)
-            .setMethodName("setGeneratedLibToken")
-            .setArguments(ValueExpr.withValue(StringObjectValue.withValue("gapic")), versionArgExpr)
-            .build();
-    returnExpr =
+    // This section is specific to GAPIC clients. It sets UseJwtAccessWithScope value to true to
+    // enable self signed JWT feature.
+    credsProviderBuilderExpr =
         MethodInvocationExpr.builder()
-            .setExprReferenceExpr(returnExpr)
-            .setMethodName("setTransportToken")
+            .setExprReferenceExpr(credsProviderBuilderExpr)
+            .setMethodName("setUseJwtAccessWithScope")
             .setArguments(
-                MethodInvocationExpr.builder()
-                    .setStaticReferenceType(
-                        FIXED_GRPC_TYPESTORE.get(GaxGrpcProperties.class.getSimpleName()))
-                    .setMethodName("getGrpcTokenName")
-                    .build(),
-                MethodInvocationExpr.builder()
-                    .setStaticReferenceType(
-                        FIXED_GRPC_TYPESTORE.get(GaxGrpcProperties.class.getSimpleName()))
-                    .setMethodName("getGrpcVersion")
-                    .build())
+                ValueExpr.withValue(
+                    PrimitiveValue.builder().setType(TypeNode.BOOLEAN).setValue("true").build()))
             .setReturnType(returnType)
             .build();
 
-    AnnotationNode annotation =
-        AnnotationNode.builder()
-            .setType(FIXED_TYPESTORE.get("BetaApi"))
-            .setDescription(
-                "The surface for customizing headers is not stable yet and may change in the"
-                    + " future.")
-            .build();
     return MethodDefinition.builder()
-        .setAnnotations(Arrays.asList(annotation))
+        .setHeaderCommentStatements(
+            SettingsCommentComposer.DEFAULT_CREDENTIALS_PROVIDER_BUILDER_METHOD_COMMENT)
         .setScope(ScopeNode.PUBLIC)
         .setIsStatic(true)
         .setReturnType(returnType)
-        .setName("defaultApiClientHeaderProviderBuilder")
-        .setReturnExpr(returnExpr)
+        .setName("defaultCredentialsProviderBuilder")
+        .setReturnExpr(credsProviderBuilderExpr)
         .build();
   }
 
+  @Override
+  protected List<MethodDefinition> createApiClientHeaderProviderBuilderMethods(
+      Service service, TypeStore typeStore) {
+    return Collections.singletonList(
+        createApiClientHeaderProviderBuilderMethod(
+            service,
+            typeStore,
+            "defaultApiClientHeaderProviderBuilder",
+            FIXED_GRPC_TYPESTORE.get(GaxGrpcProperties.class.getSimpleName()),
+            "getGrpcTokenName",
+            "getGrpcVersion"));
+  }
+
   @Override
   public MethodDefinition createDefaultTransportChannelProviderMethod() {
     TypeNode returnType = FIXED_TYPESTORE.get("TransportChannelProvider");
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/BUILD.bazel b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/BUILD.bazel
new file mode 100644
index 0000000000..ea77aab100
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/BUILD.bazel
@@ -0,0 +1,55 @@
+load("@rules_java//java:defs.bzl", "java_library")
+
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "grpcrest_files",
+    srcs = glob(["*.java"]),
+)
+
+java_library(
+    name = "grpcrest",
+    srcs = [
+        ":grpcrest_files",
+    ],
+    deps = [
+        "//:service_config_java_proto",
+        "//src/main/java/com/google/api/generator/engine/ast",
+        "//src/main/java/com/google/api/generator/engine/writer",
+        "//src/main/java/com/google/api/generator/gapic:status_java_proto",
+        "//src/main/java/com/google/api/generator/gapic/composer/comment",
+        "//src/main/java/com/google/api/generator/gapic/composer/common",
+        "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue",
+        "//src/main/java/com/google/api/generator/gapic/composer/resourcename",
+        "//src/main/java/com/google/api/generator/gapic/composer/rest",
+        "//src/main/java/com/google/api/generator/gapic/composer/samplecode",
+        "//src/main/java/com/google/api/generator/gapic/composer/store",
+        "//src/main/java/com/google/api/generator/gapic/composer/utils",
+        "//src/main/java/com/google/api/generator/gapic/model",
+        "//src/main/java/com/google/api/generator/gapic/utils",
+        "//src/main/java/com/google/api/generator/util",
+        "@com_google_api_api_common//jar",
+        "@com_google_api_gax_java//gax",
+        "@com_google_api_gax_java//gax:gax_testlib",
+        "@com_google_api_gax_java//gax-grpc:gax_grpc",
+        "@com_google_api_gax_java//gax-grpc:gax_grpc_testlib",
+        "@com_google_api_gax_java//gax-httpjson:gax_httpjson",
+        "@com_google_api_gax_java//gax-httpjson:gax_httpjson_testlib",
+        "@com_google_code_findbugs_jsr305//jar",
+        "@com_google_googleapis//gapic/metadata:metadata_java_proto",
+        "@com_google_googleapis//google/api:api_java_proto",
+        "@com_google_googleapis//google/longrunning:longrunning_java_proto",
+        "@com_google_googleapis//google/rpc:rpc_java_proto",
+        "@com_google_guava_guava//jar",
+        "@com_google_http_client_google_http_client//jar",
+        "@com_google_protobuf//:protobuf_java",
+        "@com_google_protobuf//:protobuf_java_util",
+        "@com_google_protobuf//java/core",
+        "@io_grpc_grpc_java//api",
+        "@io_grpc_grpc_java//protobuf",
+        "@io_grpc_grpc_java//stub",
+        "@javax_annotation_javax_annotation_api//jar",
+        "@junit_junit//jar",
+        "@org_threeten_threetenbp//jar",
+    ],
+)
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/GrpcRestContext.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/GrpcRestContext.java
new file mode 100644
index 0000000000..3f84bf3c97
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/GrpcRestContext.java
@@ -0,0 +1,95 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.grpc.GrpcTransportChannel;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.grpc.ProtoOperationTransformers;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.httpjson.longrunning.stub.HttpJsonOperationsStub;
+import com.google.api.generator.gapic.composer.common.TransportContext;
+import com.google.api.generator.gapic.composer.utils.ClassNames;
+import com.google.api.generator.gapic.model.Transport;
+import com.google.common.collect.ImmutableList;
+import com.google.longrunning.OperationsClient;
+import com.google.longrunning.stub.GrpcOperationsStub;
+import com.google.longrunning.stub.OperationsStub;
+
+public abstract class GrpcRestContext extends TransportContext {
+  private static final TransportContext INSTANCE =
+      GrpcRestContext.builder()
+          .setClassNames(new ClassNames("Grpc", "HttpJson"))
+          .setTransport(Transport.GRPC_REST)
+          .setTransportName(null)
+          // For grpcrest.GrpcServiceStubClassComposer
+          .setCallSettingsClass(null)
+          .setStubCallableFactoryType(null)
+          .setMethodDescriptorClass(null)
+          .setTransportOperationsStubTypes(
+              ImmutableList.of(
+                  classToType(GrpcOperationsStub.class), classToType(HttpJsonOperationsStub.class)))
+          .setTransportOperationsStubNames(
+              ImmutableList.of("operationsStub", "httpJsonOperationsStub"))
+          // For grpcrest.ServiceSettingsClassComposer
+          .setInstantiatingChannelProviderClasses(
+              ImmutableList.of(
+                  InstantiatingGrpcChannelProvider.class,
+                  InstantiatingHttpJsonChannelProvider.class))
+          .setInstantiatingChannelProviderBuilderClasses(
+              ImmutableList.of(
+                  InstantiatingGrpcChannelProvider.Builder.class,
+                  InstantiatingHttpJsonChannelProvider.Builder.class))
+          .setDefaultTransportProviderBuilderNames(
+              ImmutableList.of(
+                  "defaultGrpcTransportProviderBuilder", "defaultHttpJsonTransportProviderBuilder"))
+          .setTransportApiClientHeaderProviderBuilderNames(
+              ImmutableList.of(
+                  "defaultGrpcApiClientHeaderProviderBuilder",
+                  "defaultHttpJsonApiClientHeaderProviderBuilder"))
+          // For grpcrest.ServiceStubSettingsClassComposer
+          .setTransportChannelTypes(
+              ImmutableList.of(
+                  classToType(GrpcTransportChannel.class),
+                  classToType(HttpJsonTransportChannel.class)))
+          .setTransportGetterNames(
+              ImmutableList.of("getGrpcTransportName", "getHttpJsonTransportName"))
+          // For grpcrest.GrpcServiceCallableFactoryClassComposer
+          .setTransportCallSettingsType(null)
+          .setTransportCallableFactoryType(null)
+          .setOperationsStubTypes(
+              ImmutableList.of(
+                  classToType(OperationsStub.class), classToType(BackgroundResource.class)))
+          .setTransportCallSettingsName(null)
+          // For RetrySettingsComposer
+          // TODO: fix when LRO for REST RE FIXED
+          .setOperationResponseTransformerType(
+              classToType(ProtoOperationTransformers.ResponseTransformer.class))
+          .setOperationMetadataTransformerType(
+              classToType(ProtoOperationTransformers.MetadataTransformer.class))
+          // For ServiceClientClassComposer
+          .setOperationsClientTypes(
+              ImmutableList.of(
+                  classToType(OperationsClient.class),
+                  classToType(com.google.api.gax.httpjson.longrunning.OperationsClient.class)))
+          .setOperationsClientNames(
+              ImmutableList.of("operationsClient", "httpJsonOperationsClient"))
+          .build();
+
+  public static TransportContext instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceClientTestClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceClientTestClassComposer.java
new file mode 100644
index 0000000000..9f9bbafc05
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceClientTestClassComposer.java
@@ -0,0 +1,57 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.VariableExpr;
+import com.google.api.generator.gapic.composer.common.AbstractServiceClientTestClassComposer;
+import com.google.api.generator.gapic.composer.rest.ServiceClientTestClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Service;
+import java.util.Map;
+
+public class HttpJsonServiceClientTestClassComposer extends ServiceClientTestClassComposer {
+  private static final HttpJsonServiceClientTestClassComposer INSTANCE =
+      new HttpJsonServiceClientTestClassComposer();
+
+  protected HttpJsonServiceClientTestClassComposer() {
+    super();
+  }
+
+  public static AbstractServiceClientTestClassComposer instance() {
+    return INSTANCE;
+  }
+
+  @Override
+  protected GapicClass generate(String className, GapicContext context, Service service) {
+    return super.generate(
+        getTransportContext().classNames().getServiceClientTestClassNames(service).get(0),
+        context,
+        service);
+  }
+
+  @Override
+  protected MethodDefinition createStartStaticServerMethod(
+      Service service,
+      GapicContext context,
+      Map<String, VariableExpr> classMemberVarExprs,
+      TypeStore typeStore,
+      String newBuilderMethod) {
+    return super.createStartStaticServerMethod(
+        service, context, classMemberVarExprs, typeStore, "newHttpJsonBuilder");
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceStubClassComposer.java
new file mode 100644
index 0000000000..7f99c81287
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/HttpJsonServiceStubClassComposer.java
@@ -0,0 +1,40 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.model.Service;
+import java.util.List;
+
+public class HttpJsonServiceStubClassComposer
+    extends com.google.api.generator.gapic.composer.rest.HttpJsonServiceStubClassComposer {
+  private static final HttpJsonServiceStubClassComposer INSTANCE =
+      new HttpJsonServiceStubClassComposer();
+
+  protected HttpJsonServiceStubClassComposer() {
+    super();
+  }
+
+  public static HttpJsonServiceStubClassComposer instance() {
+    return INSTANCE;
+  }
+
+  @Override
+  protected List<MethodDefinition> createStaticCreatorMethods(
+      Service service, TypeStore typeStore, String newBuilderMethod) {
+    return super.createStaticCreatorMethods(service, typeStore, "newHttpJsonBuilder");
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceClientClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceClientClassComposer.java
new file mode 100644
index 0000000000..7529b002cf
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceClientClassComposer.java
@@ -0,0 +1,29 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.generator.gapic.composer.common.AbstractServiceClientClassComposer;
+
+public class ServiceClientClassComposer extends AbstractServiceClientClassComposer {
+  private static final ServiceClientClassComposer INSTANCE = new ServiceClientClassComposer();
+
+  protected ServiceClientClassComposer() {
+    super(GrpcRestContext.instance());
+  }
+
+  public static ServiceClientClassComposer instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceSettingsClassComposer.java
new file mode 100644
index 0000000000..03ff5dc54a
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceSettingsClassComposer.java
@@ -0,0 +1,68 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.gapic.composer.common.AbstractServiceSettingsClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.model.Service;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ServiceSettingsClassComposer extends AbstractServiceSettingsClassComposer {
+  private static final ServiceSettingsClassComposer INSTANCE = new ServiceSettingsClassComposer();
+
+  protected ServiceSettingsClassComposer() {
+    super(GrpcRestContext.instance());
+  }
+
+  public static ServiceSettingsClassComposer instance() {
+    return INSTANCE;
+  }
+
+  @Override
+  protected List<MethodDefinition> createNestedBuilderCreatorMethods(
+      Service service,
+      TypeStore typeStore,
+      String newBuilderMethodName,
+      String createDefaultMethodName) {
+    List<MethodDefinition> methods = new ArrayList<>();
+
+    methods.addAll(
+        super.createNestedBuilderCreatorMethods(service, typeStore, "newBuilder", "createDefault"));
+    methods.addAll(
+        super.createNestedBuilderCreatorMethods(
+            service, typeStore, "newHttpJsonBuilder", "createHttpJsonDefault"));
+
+    return methods;
+  }
+
+  @Override
+  protected List<MethodDefinition> createNewBuilderMethods(
+      Service service,
+      TypeStore typeStore,
+      String newBuilderMethodName,
+      String createDefaultMethodName) {
+    List<MethodDefinition> methods = new ArrayList<>();
+
+    methods.addAll(
+        super.createNewBuilderMethods(service, typeStore, "newBuilder", "createDefault"));
+    methods.addAll(
+        super.createNewBuilderMethods(
+            service, typeStore, "newHttpJsonBuilder", "createHttpJsonDefault"));
+
+    return methods;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceStubClassComposer.java
new file mode 100644
index 0000000000..6be0ef7ac2
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceStubClassComposer.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.ReturnExpr;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.gapic.composer.common.AbstractServiceStubClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+
+public class ServiceStubClassComposer extends AbstractServiceStubClassComposer {
+  private static final ServiceStubClassComposer INSTANCE = new ServiceStubClassComposer();
+
+  protected ServiceStubClassComposer() {
+    super(GrpcRestContext.instance());
+  }
+
+  public static ServiceStubClassComposer instance() {
+    return INSTANCE;
+  }
+
+  @Override
+  protected MethodDefinition createOperationsStubGetterMethodDefinition(
+      TypeNode returnType, String methodName, TypeStore typeStore) {
+    return MethodDefinition.builder()
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(returnType)
+        .setName(methodName)
+        .setReturnExpr(ReturnExpr.withExpr(ValueExpr.createNullExpr()))
+        .build();
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceStubSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceStubSettingsClassComposer.java
new file mode 100644
index 0000000000..6f65ced39c
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/grpcrest/ServiceStubSettingsClassComposer.java
@@ -0,0 +1,200 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.grpcrest;
+
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.grpc.GaxGrpcProperties;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.Expr;
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.PrimitiveValue;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.engine.ast.Variable;
+import com.google.api.generator.engine.ast.VariableExpr;
+import com.google.api.generator.gapic.composer.comment.SettingsCommentComposer;
+import com.google.api.generator.gapic.composer.common.AbstractServiceStubSettingsClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.composer.utils.ClassNames;
+import com.google.api.generator.gapic.model.Service;
+import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
+import java.util.List;
+
+public class ServiceStubSettingsClassComposer extends AbstractServiceStubSettingsClassComposer {
+  private static final ServiceStubSettingsClassComposer INSTANCE =
+      new ServiceStubSettingsClassComposer();
+
+  public static ServiceStubSettingsClassComposer instance() {
+    return INSTANCE;
+  }
+
+  protected ServiceStubSettingsClassComposer() {
+    super(GrpcRestContext.instance());
+  }
+
+  @Override
+  protected Expr initializeTransportProviderBuilder(
+      MethodInvocationExpr transportChannelProviderBuilderExpr, TypeNode returnType) {
+    if (!returnType.reference().isFromPackage("com.google.api.gax.grpc")) {
+      return transportChannelProviderBuilderExpr;
+    }
+
+    return MethodInvocationExpr.builder()
+        .setExprReferenceExpr(transportChannelProviderBuilderExpr)
+        .setMethodName("setMaxInboundMessageSize")
+        .setArguments(
+            VariableExpr.builder()
+                .setVariable(Variable.builder().setType(TypeNode.INT).setName("MAX_VALUE").build())
+                .setStaticReferenceType(TypeNode.INT_OBJECT)
+                .build())
+        .setReturnType(returnType)
+        .build();
+  }
+
+  @Override
+  protected MethodDefinition createDefaultCredentialsProviderBuilderMethod() {
+    TypeNode returnType =
+        TypeNode.withReference(
+            ConcreteReference.withClazz(GoogleCredentialsProvider.Builder.class));
+    MethodInvocationExpr credsProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(FIXED_TYPESTORE.get("GoogleCredentialsProvider"))
+            .setMethodName("newBuilder")
+            .build();
+    credsProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(credsProviderBuilderExpr)
+            .setMethodName("setScopesToApply")
+            .setArguments(DEFAULT_SERVICE_SCOPES_VAR_EXPR)
+            .setReturnType(returnType)
+            .build();
+
+    // This section is specific to GAPIC clients. It sets UseJwtAccessWithScope value to true to
+    // enable self signed JWT feature.
+    credsProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(credsProviderBuilderExpr)
+            .setMethodName("setUseJwtAccessWithScope")
+            .setArguments(
+                ValueExpr.withValue(
+                    PrimitiveValue.builder().setType(TypeNode.BOOLEAN).setValue("true").build()))
+            .setReturnType(returnType)
+            .build();
+
+    return MethodDefinition.builder()
+        .setHeaderCommentStatements(
+            SettingsCommentComposer.DEFAULT_CREDENTIALS_PROVIDER_BUILDER_METHOD_COMMENT)
+        .setScope(ScopeNode.PUBLIC)
+        .setIsStatic(true)
+        .setReturnType(returnType)
+        .setName("defaultCredentialsProviderBuilder")
+        .setReturnExpr(credsProviderBuilderExpr)
+        .build();
+  }
+
+  @Override
+  protected List<MethodDefinition> createApiClientHeaderProviderBuilderMethods(
+      Service service, TypeStore typeStore) {
+
+    TypeNode returnType =
+        TypeNode.withReference(ConcreteReference.withClazz(ApiClientHeaderProvider.Builder.class));
+
+    return ImmutableList.of(
+        createApiClientHeaderProviderBuilderMethod(
+            service,
+            typeStore,
+            "defaultGrpcApiClientHeaderProviderBuilder",
+            TypeNode.withReference(ConcreteReference.withClazz(GaxGrpcProperties.class)),
+            "getGrpcTokenName",
+            "getGrpcVersion"),
+        createApiClientHeaderProviderBuilderMethod(
+            service,
+            typeStore,
+            "defaultHttpJsonApiClientHeaderProviderBuilder",
+            TypeNode.withReference(ConcreteReference.withClazz(GaxHttpJsonProperties.class)),
+            "getHttpJsonTokenName",
+            "getHttpJsonVersion"),
+        MethodDefinition.builder()
+            .setScope(ScopeNode.PUBLIC)
+            .setIsStatic(true)
+            .setReturnType(returnType)
+            .setName("defaultApiClientHeaderProviderBuilder")
+            .setReturnExpr(
+                MethodInvocationExpr.builder()
+                    .setStaticReferenceType(
+                        typeStore.get(ClassNames.getServiceStubSettingsClassName(service)))
+                    .setMethodName("defaultGrpcApiClientHeaderProviderBuilder")
+                    .setReturnType(returnType)
+                    .build())
+            .build());
+  }
+
+  @Override
+  public MethodDefinition createDefaultTransportChannelProviderMethod() {
+    TypeNode returnType = FIXED_TYPESTORE.get("TransportChannelProvider");
+    MethodInvocationExpr transportProviderBuilderExpr =
+        MethodInvocationExpr.builder().setMethodName("defaultGrpcTransportProviderBuilder").build();
+    transportProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(transportProviderBuilderExpr)
+            .setMethodName("build")
+            .setReturnType(returnType)
+            .build();
+    return MethodDefinition.builder()
+        .setScope(ScopeNode.PUBLIC)
+        .setIsStatic(true)
+        .setReturnType(returnType)
+        .setName("defaultTransportChannelProvider")
+        .setReturnExpr(transportProviderBuilderExpr)
+        .build();
+  }
+
+  @Override
+  protected List<MethodDefinition> createNestedClassCreateDefaultMethods(TypeStore typeStore) {
+    return ImmutableList.of(
+        createNestedClassCreateDefaultMethod(
+            typeStore,
+            "createDefault",
+            "defaultTransportChannelProvider",
+            null,
+            "defaultApiClientHeaderProviderBuilder"),
+        createNestedClassCreateDefaultMethod(
+            typeStore,
+            "createHttpJsonDefault",
+            null,
+            "defaultHttpJsonTransportProviderBuilder",
+            "defaultHttpJsonApiClientHeaderProviderBuilder"));
+  }
+
+  @Override
+  protected List<MethodDefinition> createNewBuilderMethods(
+      Service service,
+      TypeStore typeStore,
+      String newBuilderMethodName,
+      String createDefaultMethodName) {
+    List<MethodDefinition> methods = new ArrayList<>();
+    methods.addAll(
+        super.createNewBuilderMethods(service, typeStore, "newBuilder", "createDefault"));
+    methods.addAll(
+        super.createNewBuilderMethods(
+            service, typeStore, "newHttpJsonBuilder", "createHttpJsonDefault"));
+    return methods;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposer.java
index 28b65cd52e..f8c961ccab 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposer.java
@@ -49,6 +49,7 @@
 import com.google.api.generator.gapic.composer.comment.CommentComposer;
 import com.google.api.generator.gapic.composer.store.TypeStore;
 import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.utils.JavaStyle;
 import com.google.api.generator.gapic.utils.ResourceNameConstants;
@@ -79,8 +80,10 @@ public class ResourceNameHelperClassComposer {
       new ResourceNameHelperClassComposer();
 
   private static final TypeStore FIXED_TYPESTORE = createStaticTypes();
+  private static final Map<String, VariableExpr> FIXED_CLASS_VARS =
+      createFixedClassMemberVariables();
 
-  private static Map<String, VariableExpr> FIXED_CLASS_VARS = createFixedClassMemberVariables();
+  private static Reference javaObjectReference = ConcreteReference.withClazz(Object.class);
 
   private ResourceNameHelperClassComposer() {}
 
@@ -88,14 +91,25 @@ public static ResourceNameHelperClassComposer instance() {
     return INSTANCE;
   }
 
-  public GapicClass generate(ResourceName resourceName) {
+  public GapicClass generate(ResourceName resourceName, GapicContext context) {
+    // Set up types.
     List<List<String>> tokenHierarchies =
         ResourceNameTokenizer.parseTokenHierarchy(resourceName.patterns());
     TypeStore typeStore = createDynamicTypes(resourceName, tokenHierarchies);
+    // Use the full name java.lang.Object if there is a proto message that is also named "Object".
+    // Affects GCS.
+    if (context.messages().keySet().stream()
+        .anyMatch(s -> s.equals("Object") || s.endsWith(".Object"))) {
+      javaObjectReference =
+          ConcreteReference.builder().setClazz(Object.class).setUseFullName(true).build();
+    }
+
+    // Set up variables.
     List<VariableExpr> templateFinalVarExprs = createTemplateClassMembers(tokenHierarchies);
     Map<String, VariableExpr> patternTokenVarExprs =
         createPatternTokenClassMembers(tokenHierarchies);
 
+    // Check invariants.
     Preconditions.checkState(
         patternTokenVarExprs.size() > 0,
         String.format("No patterns found for resource name %s", resourceName.resourceTypeString()));
@@ -200,7 +214,9 @@ private static List<Statement> createClassStatements(
     //         "projects/{project}/locations/{location}/autoscalingPolicies/{autoscaling_policy}");
     for (int i = 0; i < patterns.size(); i++) {
       VariableExpr varExpr =
-          templateFinalVarExprs.get(i).toBuilder()
+          templateFinalVarExprs
+              .get(i)
+              .toBuilder()
               .setIsDecl(true)
               .setScope(ScopeNode.PRIVATE)
               .setIsStatic(true)
@@ -224,7 +240,9 @@ private static List<Statement> createClassStatements(
     }
 
     memberVars.add(
-        FIXED_CLASS_VARS.get("fieldValuesMap").toBuilder()
+        FIXED_CLASS_VARS
+            .get("fieldValuesMap")
+            .toBuilder()
             .setIsDecl(true)
             .setScope(ScopeNode.PRIVATE)
             .setIsVolatile(true)
@@ -1174,7 +1192,6 @@ private static MethodDefinition createGetFieldValuesMapMethod(
             .build();
 
     // Outer if-block.
-    Expr thisExpr = ValueExpr.withValue(ThisObjectValue.withType(thisClassType));
     IfStatement outerIfStatement =
         IfStatement.builder()
             .setConditionExpr(fieldValuesMapNullCheckExpr)
@@ -1229,8 +1246,7 @@ private static MethodDefinition createToStringMethod(
 
       List<Expr> instantiateArgExprs = new ArrayList<>();
       List<String> tokens = getTokenSet(tokenHierarchies).stream().collect(Collectors.toList());
-      for (int i = 0; i < tokens.size(); i++) {
-        String token = tokens.get(i);
+      for (String token : tokens) {
         Preconditions.checkNotNull(
             patternTokenVarExprs.get(token),
             String.format(
@@ -1288,7 +1304,11 @@ private static MethodDefinition createToStringMethod(
   private static MethodDefinition createEqualsMethod(
       ResourceName resourceName, List<List<String>> tokenHierarchies, TypeStore typeStore) {
     // Create method definition variables.
-    Variable oVariable = Variable.builder().setType(TypeNode.OBJECT).setName("o").build();
+    Variable oVariable =
+        Variable.builder()
+            .setType(TypeNode.withReference(javaObjectReference))
+            .setName("o")
+            .build();
     VariableExpr argVarExpr =
         VariableExpr.builder().setIsDecl(false).setVariable(oVariable).build();
     TypeNode thisClassType = typeStore.get(getThisClassName(resourceName));
@@ -1550,7 +1570,6 @@ private static ClassDefinition createNestedBuilderClass(
     for (int i = 0; i < tokens.size(); i++) {
       String token = tokens.get(i);
       String upperCamelTokenName = JavaStyle.toUpperCamelCase(token);
-      String lowerCamelTokenName = JavaStyle.toLowerCamelCase(token);
       VariableExpr currClassTokenVarExpr = classMemberVarExprs.get(i);
 
       // Getter.
@@ -1603,7 +1622,9 @@ private static ClassDefinition createNestedBuilderClass(
                 .setStaticReferenceType(FIXED_TYPESTORE.get("Objects"))
                 .setMethodName("equals")
                 .setArguments(
-                    FIXED_CLASS_VARS.get("pathTemplate").toBuilder()
+                    FIXED_CLASS_VARS
+                        .get("pathTemplate")
+                        .toBuilder()
                         .setExprReferenceExpr(outerClassVarExpr)
                         .build(),
                     templateFinalVarExpr)
@@ -1623,15 +1644,15 @@ private static ClassDefinition createNestedBuilderClass(
                 .build());
       }
 
-      for (int i = 0; i < tokens.size(); i++) {
-        String token = tokens.get(i);
-        String lowerCamelTokenName = JavaStyle.toLowerCamelCase(token);
-        VariableExpr currClassTokenVarExpr = classMemberVarExprs.get(i);
+      for (VariableExpr memberVarExpr : classMemberVarExprs) {
+        VariableExpr currClassTokenVarExpr =
+            memberVarExpr.toBuilder().setExprReferenceExpr(thisExpr).build();
         builderCtorBodyExprs.add(
             AssignmentExpr.builder()
                 .setVariableExpr(currClassTokenVarExpr)
                 .setValueExpr(
-                    currClassTokenVarExpr.toBuilder()
+                    currClassTokenVarExpr
+                        .toBuilder()
                         .setExprReferenceExpr(outerClassVarExpr)
                         .build())
                 .build());
@@ -1687,7 +1708,7 @@ private static ClassDefinition createNestedBuilderClass(
   }
 
   private static TypeStore createStaticTypes() {
-    List<Class> concreteClazzes =
+    List<Class<?>> concreteClazzes =
         Arrays.asList(
             ArrayList.class,
             BetaApi.class,
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/BUILD.bazel b/src/main/java/com/google/api/generator/gapic/composer/rest/BUILD.bazel
new file mode 100644
index 0000000000..4b9e29239c
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/BUILD.bazel
@@ -0,0 +1,52 @@
+load("@rules_java//java:defs.bzl", "java_library")
+
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "rest_files",
+    srcs = glob(["*.java"]),
+)
+
+java_library(
+    name = "rest",
+    srcs = [
+        ":rest_files",
+    ],
+    deps = [
+        "//:service_config_java_proto",
+        "//src/main/java/com/google/api/generator/engine/ast",
+        "//src/main/java/com/google/api/generator/engine/writer",
+        "//src/main/java/com/google/api/generator/gapic:status_java_proto",
+        "//src/main/java/com/google/api/generator/gapic/composer/comment",
+        "//src/main/java/com/google/api/generator/gapic/composer/common",
+        "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue",
+        "//src/main/java/com/google/api/generator/gapic/composer/resourcename",
+        "//src/main/java/com/google/api/generator/gapic/composer/samplecode",
+        "//src/main/java/com/google/api/generator/gapic/composer/store",
+        "//src/main/java/com/google/api/generator/gapic/composer/utils",
+        "//src/main/java/com/google/api/generator/gapic/model",
+        "//src/main/java/com/google/api/generator/gapic/utils",
+        "//src/main/java/com/google/api/generator/util",
+        "@com_google_api_api_common//jar",
+        "@com_google_api_gax_java//gax",
+        "@com_google_api_gax_java//gax:gax_testlib",
+        "@com_google_api_gax_java//gax-httpjson:gax_httpjson",
+        "@com_google_api_gax_java//gax-httpjson:gax_httpjson_testlib",
+        "@com_google_code_findbugs_jsr305//jar",
+        "@com_google_googleapis//gapic/metadata:metadata_java_proto",
+        "@com_google_googleapis//google/api:api_java_proto",
+        "@com_google_googleapis//google/longrunning:longrunning_java_proto",
+        "@com_google_googleapis//google/rpc:rpc_java_proto",
+        "@com_google_guava_guava//jar",
+        "@com_google_http_client_google_http_client//jar",
+        "@com_google_protobuf//:protobuf_java",
+        "@com_google_protobuf//:protobuf_java_util",
+        "@com_google_protobuf//java/core",
+        "@io_grpc_grpc_java//api",
+        "@io_grpc_grpc_java//protobuf",
+        "@io_grpc_grpc_java//stub",
+        "@javax_annotation_javax_annotation_api//jar",
+        "@junit_junit//jar",
+        "@org_threeten_threetenbp//jar",
+    ],
+)
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposer.java
new file mode 100644
index 0000000000..1ed6296cfa
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposer.java
@@ -0,0 +1,107 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.gax.httpjson.ApiMessage;
+import com.google.api.generator.engine.ast.AnnotationNode;
+import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.gapic.composer.common.AbstractServiceCallableFactoryClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.model.Service;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class HttpJsonServiceCallableFactoryClassComposer
+    extends AbstractServiceCallableFactoryClassComposer {
+  private static final HttpJsonServiceCallableFactoryClassComposer INSTANCE =
+      new HttpJsonServiceCallableFactoryClassComposer();
+
+  private static final TypeNode MESSAGE_TYPE =
+      TypeNode.withReference(ConcreteReference.withClazz(ApiMessage.class));
+
+  private HttpJsonServiceCallableFactoryClassComposer() {
+    super(RestContext.instance());
+  }
+
+  public static HttpJsonServiceCallableFactoryClassComposer instance() {
+    return INSTANCE;
+  }
+
+  @Override
+  protected List<AnnotationNode> createClassAnnotations(Service service, TypeStore typeStore) {
+    List<AnnotationNode> annotations = super.createClassAnnotations(service, typeStore);
+    // Always add @BetaApi annotation to the generated CallableFactory for now. It is a public class
+    // for technical reasons, end users are not expected to interact with it, but it may change
+    // when we add LRO support, that is why making it @BetaApi for now.
+    //
+    // Remove the @BetaApi annotation once the LRO feature is fully implemented and stabilized.
+    if (annotations.stream().noneMatch(a -> a.type().equals(typeStore.get("BetaApi")))) {
+      annotations.add(AnnotationNode.withType(typeStore.get("BetaApi")));
+    }
+    return annotations;
+  }
+
+  @Override
+  protected List<TypeNode> createClassImplements(TypeStore typeStore) {
+    return Arrays.asList(
+        TypeNode.withReference(
+            getTransportContext()
+                .stubCallableFactoryType()
+                .reference()
+                .copyAndSetGenerics(
+                    Arrays.asList(
+                        MESSAGE_TYPE.reference(),
+                        getTransportContext().operationsStubTypes().get(0).reference()))));
+  }
+
+  @Override
+  protected MethodDefinition createOperationCallableMethod(TypeStore typeStore) {
+    String methodVariantName = "Operation";
+    String requestTemplateName = "RequestT";
+    String responseTemplateName = "ResponseT";
+    List<String> methodTemplateNames =
+        Arrays.asList(requestTemplateName, responseTemplateName, "MetadataT");
+
+    // Always add @BetaApi annotation to the generated createOperationCallable() method for now,
+    // until LRO is fully implemented.
+    //
+    // Remove the @BetaApi annotation once the LRO feature is fully implemented and stabilized.
+    AnnotationNode betaAnnotation =
+        AnnotationNode.withTypeAndDescription(
+            typeStore.get("BetaApi"),
+            "The surface for long-running operations is not stable yet and may change in the"
+                + " future.");
+
+    MethodDefinition method =
+        createGenericCallableMethod(
+            typeStore,
+            /*methodTemplateNames=*/ methodTemplateNames,
+            /*returnCallableKindName=*/ methodVariantName,
+            /*returnCallableTemplateNames=*/ methodTemplateNames,
+            /*methodVariantName=*/ methodVariantName,
+            /*httpJsonCallSettingsTemplateObjects=*/ Arrays.asList(
+                requestTemplateName, MESSAGE_TYPE),
+            /*callSettingsVariantName=*/ methodVariantName,
+            /*callSettingsTemplateObjects=*/ methodTemplateNames.stream()
+                .map(n -> (Object) n)
+                .collect(Collectors.toList()),
+            Arrays.asList(betaAnnotation));
+    return method.toBuilder().setReturnExpr(ValueExpr.createNullExpr()).build();
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceStubClassComposer.java
new file mode 100644
index 0000000000..50ea1ad57e
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceStubClassComposer.java
@@ -0,0 +1,617 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.client.http.HttpMethods;
+import com.google.api.core.InternalApi;
+import com.google.api.gax.httpjson.ApiMethodDescriptor;
+import com.google.api.gax.httpjson.FieldsExtractor;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.httpjson.ProtoMessageRequestFormatter;
+import com.google.api.gax.httpjson.ProtoMessageResponseParser;
+import com.google.api.gax.httpjson.ProtoRestSerializer;
+import com.google.api.generator.engine.ast.AnnotationNode;
+import com.google.api.generator.engine.ast.AssignmentExpr;
+import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.EnumRefExpr;
+import com.google.api.generator.engine.ast.Expr;
+import com.google.api.generator.engine.ast.ExprStatement;
+import com.google.api.generator.engine.ast.IfStatement;
+import com.google.api.generator.engine.ast.LambdaExpr;
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.NewObjectExpr;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.ast.Statement;
+import com.google.api.generator.engine.ast.StringObjectValue;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.engine.ast.Variable;
+import com.google.api.generator.engine.ast.VariableExpr;
+import com.google.api.generator.gapic.composer.common.AbstractTransportServiceStubClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.model.HttpBindings.HttpBinding;
+import com.google.api.generator.gapic.model.Method;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.utils.JavaStyle;
+import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+public class HttpJsonServiceStubClassComposer extends AbstractTransportServiceStubClassComposer {
+  private static final HttpJsonServiceStubClassComposer INSTANCE =
+      new HttpJsonServiceStubClassComposer();
+
+  private static final TypeStore FIXED_REST_TYPESTORE = createStaticTypes();
+
+  protected HttpJsonServiceStubClassComposer() {
+    super(RestContext.instance());
+  }
+
+  public static HttpJsonServiceStubClassComposer instance() {
+    return INSTANCE;
+  }
+
+  private static TypeStore createStaticTypes() {
+    return new TypeStore(
+        Arrays.asList(
+            ApiMethodDescriptor.class,
+            ArrayList.class,
+            FieldsExtractor.class,
+            InternalApi.class,
+            HashMap.class,
+            HttpJsonCallSettings.class,
+            HttpJsonStubCallableFactory.class,
+            Map.class,
+            ProtoMessageRequestFormatter.class,
+            ProtoMessageResponseParser.class,
+            ProtoRestSerializer.class));
+  }
+
+  @Override
+  protected boolean generateOperationsStubLogic(Service service) {
+    return service.hasLroMethods();
+  }
+
+  @Override
+  protected Statement createMethodDescriptorVariableDecl(
+      Service service, Method protoMethod, VariableExpr methodDescriptorVarExpr) {
+    MethodInvocationExpr expr =
+        MethodInvocationExpr.builder()
+            .setMethodName("newBuilder")
+            .setStaticReferenceType(
+                FIXED_REST_TYPESTORE.get(ApiMethodDescriptor.class.getSimpleName()))
+            .setGenerics(methodDescriptorVarExpr.variable().type().reference().generics())
+            .build();
+
+    BiFunction<String, List<Expr>, Function<MethodInvocationExpr, MethodInvocationExpr>>
+        methodMaker = getMethodMaker();
+
+    String codeMethodArgName = getProtoRpcFullMethodName(service, protoMethod);
+    expr =
+        methodMaker
+            .apply(
+                "setFullMethodName",
+                Arrays.asList(ValueExpr.withValue(StringObjectValue.withValue(codeMethodArgName))))
+            .apply(expr);
+
+    expr = methodMaker.apply("setHttpMethod", getHttpMethodTypeExpr(protoMethod)).apply(expr);
+    expr =
+        methodMaker.apply("setRequestFormatter", getRequestFormatterExpr(protoMethod)).apply(expr);
+    expr = methodMaker.apply("setResponseParser", setResponseParserExpr(protoMethod)).apply(expr);
+
+    expr =
+        MethodInvocationExpr.builder()
+            .setMethodName("build")
+            .setExprReferenceExpr(expr)
+            .setReturnType(methodDescriptorVarExpr.type())
+            .build();
+
+    return ExprStatement.withExpr(
+        AssignmentExpr.builder()
+            .setVariableExpr(
+                methodDescriptorVarExpr
+                    .toBuilder()
+                    .setIsDecl(true)
+                    .setScope(ScopeNode.PRIVATE)
+                    .setIsStatic(true)
+                    .setIsFinal(true)
+                    .build())
+            .setValueExpr(expr)
+            .build());
+  }
+
+  @Override
+  protected Expr createTransportSettingsInitExpr(
+      Method method, VariableExpr transportSettingsVarExpr, VariableExpr methodDescriptorVarExpr) {
+    MethodInvocationExpr callSettingsBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(
+                FIXED_REST_TYPESTORE.get(HttpJsonCallSettings.class.getSimpleName()))
+            .setGenerics(transportSettingsVarExpr.type().reference().generics())
+            .setMethodName("newBuilder")
+            .build();
+    callSettingsBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(callSettingsBuilderExpr)
+            .setMethodName("setMethodDescriptor")
+            .setArguments(Arrays.asList(methodDescriptorVarExpr))
+            .build();
+
+    callSettingsBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(callSettingsBuilderExpr)
+            .setMethodName("build")
+            .setReturnType(transportSettingsVarExpr.type())
+            .build();
+    return AssignmentExpr.builder()
+        .setVariableExpr(transportSettingsVarExpr.toBuilder().setIsDecl(true).build())
+        .setValueExpr(callSettingsBuilderExpr)
+        .build();
+  }
+
+  @Override
+  protected List<AnnotationNode> createClassAnnotations(Service service) {
+    List<AnnotationNode> annotations = super.createClassAnnotations(service);
+
+    annotations.add(
+        AnnotationNode.builder()
+            .setType(FIXED_TYPESTORE.get("BetaApi"))
+            .setDescription(
+                "A restructuring of stub classes is planned, so this may break in the future")
+            .build());
+    return annotations;
+  }
+
+  @Override
+  protected List<MethodDefinition> createGetMethodDescriptorsMethod(
+      Service service,
+      TypeStore typeStore,
+      Map<String, VariableExpr> protoMethodNameToDescriptorVarExprs) {
+
+    List<Expr> bodyExprs = new ArrayList<>();
+
+    VariableExpr methodDescriptorsVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setType(
+                    TypeNode.withReference(
+                        ConcreteReference.builder()
+                            .setClazz(List.class)
+                            .setGenerics(
+                                Arrays.asList(
+                                    FIXED_REST_TYPESTORE.get("ApiMethodDescriptor").reference()))
+                            .build()))
+                .setName("methodDescriptors")
+                .build());
+
+    bodyExprs.add(
+        AssignmentExpr.builder()
+            .setVariableExpr(methodDescriptorsVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(
+                NewObjectExpr.builder()
+                    .setType(FIXED_REST_TYPESTORE.get("ArrayList"))
+                    .setIsGeneric(true)
+                    .build())
+            .build());
+
+    for (VariableExpr methodDescriptorVarExpr : protoMethodNameToDescriptorVarExprs.values()) {
+      bodyExprs.add(
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(methodDescriptorsVarExpr)
+              .setMethodName("add")
+              .setArguments(methodDescriptorVarExpr)
+              .build());
+    }
+
+    return Arrays.asList(
+        MethodDefinition.builder()
+            .setScope(ScopeNode.PUBLIC)
+            .setIsStatic(true)
+            .setReturnType(methodDescriptorsVarExpr.type())
+            .setReturnExpr(methodDescriptorsVarExpr)
+            .setAnnotations(
+                Arrays.asList(AnnotationNode.withType(FIXED_REST_TYPESTORE.get("InternalApi"))))
+            .setName("getMethodDescriptors")
+            .setBody(bodyExprs.stream().map(ExprStatement::withExpr).collect(Collectors.toList()))
+            .build());
+  }
+
+  private BiFunction<String, List<Expr>, Function<MethodInvocationExpr, MethodInvocationExpr>>
+      getMethodMaker() {
+    return (mName, argExpr) ->
+        (m) ->
+            MethodInvocationExpr.builder()
+                .setMethodName(mName)
+                .setArguments(argExpr)
+                .setExprReferenceExpr(m)
+                .build();
+  }
+
+  private List<Expr> getRequestFormatterExpr(Method protoMethod) {
+    BiFunction<String, List<Expr>, Function<MethodInvocationExpr, MethodInvocationExpr>>
+        methodMaker = getMethodMaker();
+
+    MethodInvocationExpr expr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(
+                FIXED_REST_TYPESTORE.get(ProtoMessageRequestFormatter.class.getSimpleName()))
+            .setMethodName("newBuilder")
+            .setGenerics(Collections.singletonList(protoMethod.inputType().reference()))
+            .build();
+
+    TypeNode extractorVarType =
+        TypeNode.withReference(
+            ConcreteReference.builder()
+                .setClazz(Map.class)
+                .setGenerics(TypeNode.STRING.reference(), TypeNode.STRING.reference())
+                .build());
+
+    expr =
+        methodMaker
+            .apply(
+                "setPath",
+                Arrays.asList(
+                    ValueExpr.withValue(
+                        StringObjectValue.withValue(
+                            protoMethod.httpBindings().patternLowerCamel())),
+                    createFieldsExtractorClassInstance(
+                        protoMethod,
+                        extractorVarType,
+                        protoMethod.httpBindings().pathParameters(),
+                        "putPathParam")))
+            .apply(expr);
+
+    TypeNode fieldsVarGenericType =
+        TypeNode.withReference(
+            ConcreteReference.builder()
+                .setClazz(List.class)
+                .setGenerics(TypeNode.STRING.reference())
+                .build());
+
+    extractorVarType =
+        TypeNode.withReference(
+            ConcreteReference.builder()
+                .setClazz(Map.class)
+                .setGenerics(TypeNode.STRING.reference(), fieldsVarGenericType.reference())
+                .build());
+
+    expr =
+        methodMaker
+            .apply(
+                "setQueryParamsExtractor",
+                Arrays.asList(
+                    createFieldsExtractorClassInstance(
+                        protoMethod,
+                        extractorVarType,
+                        protoMethod.httpBindings().queryParameters(),
+                        "putQueryParam")))
+            .apply(expr);
+
+    extractorVarType = TypeNode.STRING;
+    boolean asteriskBody = protoMethod.httpBindings().isAsteriskBody();
+    expr =
+        methodMaker
+            .apply(
+                "setRequestBodyExtractor",
+                Arrays.asList(
+                    createBodyFieldsExtractorClassInstance(
+                        protoMethod,
+                        extractorVarType,
+                        asteriskBody
+                            ? protoMethod.httpBindings().pathParameters()
+                            : protoMethod.httpBindings().bodyParameters(),
+                        "toBody",
+                        asteriskBody)))
+            .apply(expr);
+    expr = methodMaker.apply("build", Collections.emptyList()).apply(expr);
+
+    return Collections.singletonList(expr);
+  }
+
+  private List<Expr> setResponseParserExpr(Method protoMethod) {
+    BiFunction<String, List<Expr>, Function<MethodInvocationExpr, MethodInvocationExpr>>
+        methodMaker = getMethodMaker();
+
+    MethodInvocationExpr expr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(
+                FIXED_REST_TYPESTORE.get(ProtoMessageResponseParser.class.getSimpleName()))
+            .setMethodName("newBuilder")
+            .setGenerics(Collections.singletonList(protoMethod.outputType().reference()))
+            // .setArguments(Arrays.asList(m))
+            .build();
+
+    expr =
+        methodMaker
+            .apply(
+                "setDefaultInstance",
+                Arrays.asList(
+                    MethodInvocationExpr.builder()
+                        .setStaticReferenceType(protoMethod.outputType())
+                        .setMethodName("getDefaultInstance")
+                        .setReturnType(protoMethod.outputType())
+                        .build()))
+            .apply(expr);
+    expr = methodMaker.apply("build", Collections.emptyList()).apply(expr);
+
+    return Collections.singletonList(expr);
+  }
+
+  private Expr createBodyFieldsExtractorClassInstance(
+      Method method,
+      TypeNode extractorReturnType,
+      Set<HttpBinding> httpBindingFieldNames,
+      String serializerMethodName,
+      boolean asteriskBody) {
+    List<Statement> bodyStatements = new ArrayList<>();
+
+    Expr returnExpr = null;
+    Expr serializerExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("create")
+            .setStaticReferenceType(
+                FIXED_REST_TYPESTORE.get(ProtoRestSerializer.class.getSimpleName()))
+            .build();
+
+    VariableExpr requestVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setType(method.inputType()).setName("request").build());
+    Expr bodyRequestExpr = requestVarExpr;
+    String requestMethodPrefix = "get";
+    String bodyParamName = null;
+
+    if (asteriskBody) {
+      bodyRequestExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(requestVarExpr)
+              .setMethodName("toBuilder")
+              .build();
+      // In case of `body: "*"` case we send the whole request message as a body, minus the fields
+      // in the path, therefore the "clear" prefix here.
+      requestMethodPrefix = "clear";
+    }
+
+    Expr prevExpr = bodyRequestExpr;
+    for (HttpBinding httpBindingFieldName : httpBindingFieldNames) {
+      // Handle foo.bar cases by descending into the subfields.
+      MethodInvocationExpr.Builder requestFieldMethodExprBuilder =
+          MethodInvocationExpr.builder().setExprReferenceExpr(prevExpr);
+      bodyParamName = JavaStyle.toLowerCamelCase(httpBindingFieldName.name());
+      String[] descendantFields = httpBindingFieldName.name().split("\\.");
+      if (asteriskBody && descendantFields.length > 1) {
+        // This is the `body: "*"` case, do not clean nested body fields as it a very rare, not
+        // well-defined case, and it is generally safer to send more than less in such case.
+        continue;
+      }
+
+      for (int i = 0; i < descendantFields.length; i++) {
+        String currFieldName = descendantFields[i];
+        String bindingFieldMethodName =
+            String.format("%s%s", requestMethodPrefix, JavaStyle.toUpperCamelCase(currFieldName));
+        requestFieldMethodExprBuilder =
+            requestFieldMethodExprBuilder.setMethodName(bindingFieldMethodName);
+
+        if (i < descendantFields.length - 1) {
+          requestFieldMethodExprBuilder =
+              MethodInvocationExpr.builder()
+                  .setExprReferenceExpr(requestFieldMethodExprBuilder.build());
+        }
+      }
+      prevExpr = requestFieldMethodExprBuilder.build();
+    }
+
+    if (httpBindingFieldNames.isEmpty() && !asteriskBody) {
+      returnExpr = ValueExpr.createNullExpr();
+    } else {
+      ImmutableList.Builder<Expr> paramsPutArgs = ImmutableList.builder();
+      if (asteriskBody) {
+        prevExpr =
+            MethodInvocationExpr.builder()
+                .setExprReferenceExpr(prevExpr)
+                .setMethodName("build")
+                .build();
+        bodyParamName = "*";
+      }
+      paramsPutArgs.add(ValueExpr.withValue(StringObjectValue.withValue(bodyParamName)));
+      paramsPutArgs.add(prevExpr);
+
+      returnExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(serializerExpr)
+              .setMethodName(serializerMethodName)
+              .setArguments(paramsPutArgs.build())
+              .setReturnType(extractorReturnType)
+              .build();
+    }
+
+    // Overrides FieldsExtractor
+    // (https://github.com/googleapis/gax-java/blob/12b18ee255d3fabe13bb3969df40753b29f830d5/gax-httpjson/src/main/java/com/google/api/gax/httpjson/FieldsExtractor.java).
+    return LambdaExpr.builder()
+        .setArguments(requestVarExpr.toBuilder().setIsDecl(true).build())
+        .setBody(bodyStatements)
+        .setReturnExpr(returnExpr)
+        .build();
+  }
+
+  private Expr createFieldsExtractorClassInstance(
+      Method method,
+      TypeNode extractorReturnType,
+      Set<HttpBinding> httpBindingFieldNames,
+      String serializerMethodName) {
+    List<Statement> bodyStatements = new ArrayList<>();
+
+    VariableExpr fieldsVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("fields").setType(extractorReturnType).build());
+    Expr fieldsAssignExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(fieldsVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(
+                NewObjectExpr.builder()
+                    .setType(FIXED_REST_TYPESTORE.get(HashMap.class.getSimpleName()))
+                    .setIsGeneric(true)
+                    .build())
+            .build();
+
+    bodyStatements.add(ExprStatement.withExpr(fieldsAssignExpr));
+
+    TypeNode serializerVarType =
+        TypeNode.withReference(
+            ConcreteReference.builder()
+                .setClazz(ProtoRestSerializer.class)
+                .setGenerics(method.inputType().reference())
+                .build());
+
+    VariableExpr serializerVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("serializer").setType(serializerVarType).build());
+
+    Expr serializerAssignExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(serializerVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(
+                MethodInvocationExpr.builder()
+                    .setStaticReferenceType(
+                        FIXED_REST_TYPESTORE.get(ProtoRestSerializer.class.getSimpleName()))
+                    .setMethodName("create")
+                    .setReturnType(serializerVarType)
+                    .build())
+            .build();
+
+    bodyStatements.add(ExprStatement.withExpr(serializerAssignExpr));
+
+    VariableExpr requestVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setType(method.inputType()).setName("request").build());
+
+    for (HttpBinding httpBindingFieldName : httpBindingFieldNames) {
+      // Handle foo.bar cases by descending into the subfields.
+      MethodInvocationExpr.Builder requestFieldGetterExprBuilder =
+          MethodInvocationExpr.builder().setExprReferenceExpr(requestVarExpr);
+      MethodInvocationExpr.Builder requestFieldHasExprBuilder =
+          MethodInvocationExpr.builder().setExprReferenceExpr(requestVarExpr);
+      String[] descendantFields = httpBindingFieldName.name().split("\\.");
+      for (int i = 0; i < descendantFields.length; i++) {
+        String currFieldName = descendantFields[i];
+        String bindingFieldMethodName =
+            String.format("get%s", JavaStyle.toUpperCamelCase(currFieldName));
+        requestFieldGetterExprBuilder =
+            requestFieldGetterExprBuilder.setMethodName(bindingFieldMethodName);
+
+        String bindingFieldHasMethodName =
+            (i < descendantFields.length - 1)
+                ? bindingFieldMethodName
+                : String.format("has%s", JavaStyle.toUpperCamelCase(currFieldName));
+        requestFieldHasExprBuilder =
+            requestFieldHasExprBuilder
+                .setMethodName(bindingFieldHasMethodName)
+                .setReturnType(TypeNode.BOOLEAN);
+
+        if (i < descendantFields.length - 1) {
+          requestFieldGetterExprBuilder =
+              MethodInvocationExpr.builder()
+                  .setExprReferenceExpr(requestFieldGetterExprBuilder.build());
+          requestFieldHasExprBuilder =
+              MethodInvocationExpr.builder()
+                  .setExprReferenceExpr(requestFieldHasExprBuilder.build());
+        }
+      }
+
+      MethodInvocationExpr requestBuilderExpr = requestFieldGetterExprBuilder.build();
+      MethodInvocationExpr requestHasExpr = requestFieldHasExprBuilder.build();
+
+      ImmutableList.Builder<Expr> paramsPutArgs = ImmutableList.builder();
+
+      paramsPutArgs.add(fieldsVarExpr);
+
+      paramsPutArgs.add(
+          ValueExpr.withValue(
+              StringObjectValue.withValue(
+                  JavaStyle.toLowerCamelCase(httpBindingFieldName.name()))));
+      paramsPutArgs.add(requestBuilderExpr);
+
+      Expr paramsPutExpr =
+          MethodInvocationExpr.builder()
+              .setExprReferenceExpr(serializerVarExpr)
+              .setMethodName(serializerMethodName)
+              .setArguments(paramsPutArgs.build())
+              .setReturnType(extractorReturnType)
+              .build();
+
+      if (httpBindingFieldName.isOptional()) {
+        bodyStatements.add(
+            IfStatement.builder()
+                .setConditionExpr(requestHasExpr)
+                .setBody(Arrays.asList(ExprStatement.withExpr(paramsPutExpr)))
+                .build());
+      } else {
+        bodyStatements.add(ExprStatement.withExpr(paramsPutExpr));
+      }
+    }
+
+    // Overrides FieldsExtractor
+    // (https://github.com/googleapis/gax-java/blob/12b18ee255d3fabe13bb3969df40753b29f830d5/gax-httpjson/src/main/java/com/google/api/gax/httpjson/FieldsExtractor.java).
+    return LambdaExpr.builder()
+        .setArguments(requestVarExpr.toBuilder().setIsDecl(true).build())
+        .setBody(bodyStatements)
+        .setReturnExpr(fieldsVarExpr)
+        .build();
+  }
+
+  private List<Expr> getHttpMethodTypeExpr(Method protoMethod) {
+    EnumRefExpr expr =
+        EnumRefExpr.builder()
+            .setName(protoMethod.httpBindings().httpVerb().toString())
+            .setType(
+                TypeNode.withReference(
+                    ConcreteReference.builder().setClazz(HttpMethods.class).build()))
+            .build();
+    return Collections.singletonList(expr);
+  }
+
+  @Override
+  protected Optional<String> getCallableCreatorMethodName(TypeNode callableVarExprType) {
+    final String typeName = callableVarExprType.reference().name();
+    String streamName = "Unary";
+
+    // Special handling for pagination methods.
+    if (callableVarExprType.reference().generics().size() == 2
+        && callableVarExprType.reference().generics().get(1).name().endsWith("PagedResponse")) {
+      streamName = "Paged";
+    } else {
+      if (typeName.startsWith("Client")) {
+        return Optional.empty(); // not supported in REST transport
+      } else if (typeName.startsWith("Server")) {
+        return Optional.empty(); // not supported in REST transport (for now)
+      } else if (typeName.startsWith("Bidi")) {
+        return Optional.empty(); // not supported in REST transport
+      } else if (typeName.startsWith("Operation")) {
+        streamName = "Operation";
+      }
+    }
+    return Optional.of(String.format("create%sCallable", streamName));
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/RestContext.java b/src/main/java/com/google/api/generator/gapic/composer/rest/RestContext.java
new file mode 100644
index 0000000000..eab59215bf
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/RestContext.java
@@ -0,0 +1,76 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.httpjson.ApiMethodDescriptor;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonCallableFactory;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.httpjson.ProtoOperationTransformers;
+import com.google.api.gax.httpjson.longrunning.OperationsClient;
+import com.google.api.gax.httpjson.longrunning.stub.HttpJsonOperationsStub;
+import com.google.api.generator.gapic.composer.common.TransportContext;
+import com.google.api.generator.gapic.composer.utils.ClassNames;
+import com.google.api.generator.gapic.model.Transport;
+import com.google.common.collect.ImmutableList;
+
+public abstract class RestContext extends TransportContext {
+  private static final TransportContext INSTANCE =
+      RestContext.builder()
+          .setClassNames(new ClassNames("HttpJson"))
+          .setTransport(Transport.REST)
+          .setTransportName("REST")
+          // For httpjson.HttpJsonServiceStubClassComposer
+          .setCallSettingsClass(HttpJsonCallSettings.class)
+          .setStubCallableFactoryType(classToType(HttpJsonStubCallableFactory.class))
+          .setMethodDescriptorClass(ApiMethodDescriptor.class)
+          .setTransportOperationsStubTypes(
+              ImmutableList.of(classToType(HttpJsonOperationsStub.class)))
+          .setTransportOperationsStubNames(ImmutableList.of("httpJsonOperationsStub"))
+          // For httpjson.ServiceSettingsClassComposer
+          .setInstantiatingChannelProviderClasses(
+              ImmutableList.of(InstantiatingHttpJsonChannelProvider.class))
+          .setInstantiatingChannelProviderBuilderClasses(
+              ImmutableList.of(InstantiatingHttpJsonChannelProvider.Builder.class))
+          .setDefaultTransportProviderBuilderNames(
+              ImmutableList.of("defaultHttpJsonTransportProviderBuilder"))
+          .setTransportApiClientHeaderProviderBuilderNames(
+              ImmutableList.of("defaultHttpJsonApiClientHeaderProviderBuilder"))
+          // For httpjson.ServiceStubSettingsClassComposer
+          .setTransportChannelTypes(ImmutableList.of(classToType(HttpJsonTransportChannel.class)))
+          .setTransportGetterNames(ImmutableList.of("getHttpJsonTransportName"))
+          // For httpjson.HttpJsonServiceCallableFactoryClassComposer
+          .setTransportCallSettingsType(classToType(HttpJsonCallSettings.class))
+          .setTransportCallableFactoryType(classToType(HttpJsonCallableFactory.class))
+          // TODO: set to com.google.api.gax.httpjson.longrunning.stub.OperationsStub.class
+          .setOperationsStubTypes(ImmutableList.of(classToType(BackgroundResource.class)))
+          .setTransportCallSettingsName("httpJsonCallSettings")
+          // For RetrySettingsComposer
+          .setOperationResponseTransformerType(
+              classToType(ProtoOperationTransformers.ResponseTransformer.class))
+          .setOperationMetadataTransformerType(
+              classToType(ProtoOperationTransformers.MetadataTransformer.class))
+          // For ServiceClientClassComposer
+          .setOperationsClientTypes(ImmutableList.of(classToType(OperationsClient.class)))
+          .setOperationsClientNames(ImmutableList.of("httpJsonOperationsClient"))
+          .build();
+
+  public static TransportContext instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceClientClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceClientClassComposer.java
new file mode 100644
index 0000000000..9b5f996db7
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceClientClassComposer.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.gapic.composer.common.AbstractServiceClientClassComposer;
+
+public class ServiceClientClassComposer extends AbstractServiceClientClassComposer {
+  private static final ServiceClientClassComposer INSTANCE = new ServiceClientClassComposer();
+
+  protected ServiceClientClassComposer() {
+    super(RestContext.instance());
+  }
+
+  public static ServiceClientClassComposer instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceClientTestClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceClientTestClassComposer.java
new file mode 100644
index 0000000000..9df088bbd7
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceClientTestClassComposer.java
@@ -0,0 +1,544 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.gax.httpjson.ApiMethodDescriptor;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.testing.MockHttpService;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ApiException;
+import com.google.api.gax.rpc.ApiExceptionFactory;
+import com.google.api.gax.rpc.StatusCode.Code;
+import com.google.api.gax.rpc.testing.FakeStatusCode;
+import com.google.api.generator.engine.ast.AnnotationNode;
+import com.google.api.generator.engine.ast.AssignmentExpr;
+import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.EnumRefExpr;
+import com.google.api.generator.engine.ast.Expr;
+import com.google.api.generator.engine.ast.ExprStatement;
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.NewObjectExpr;
+import com.google.api.generator.engine.ast.PrimitiveValue;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.ast.Statement;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.engine.ast.ValueExpr;
+import com.google.api.generator.engine.ast.Variable;
+import com.google.api.generator.engine.ast.VariableExpr;
+import com.google.api.generator.gapic.composer.common.AbstractServiceClientTestClassComposer;
+import com.google.api.generator.gapic.composer.defaultvalue.DefaultValueComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.composer.utils.ClassNames;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Message;
+import com.google.api.generator.gapic.model.Method;
+import com.google.api.generator.gapic.model.MethodArgument;
+import com.google.api.generator.gapic.model.ResourceName;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.utils.JavaStyle;
+import com.google.common.collect.ImmutableList;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiFunction;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+public class ServiceClientTestClassComposer extends AbstractServiceClientTestClassComposer {
+  private static final String MOCK_SERVICE_VAR_NAME = "mockService";
+
+  private static final ServiceClientTestClassComposer INSTANCE =
+      new ServiceClientTestClassComposer();
+
+  private static final TypeStore FIXED_REST_TYPESTORE = createStaticTypes();
+
+  protected ServiceClientTestClassComposer() {
+    super(RestContext.instance());
+  }
+
+  public static AbstractServiceClientTestClassComposer instance() {
+    return INSTANCE;
+  }
+
+  private static TypeStore createStaticTypes() {
+    return new TypeStore(
+        Arrays.asList(
+            ApiClientHeaderProvider.class,
+            ApiException.class,
+            ApiExceptionFactory.class,
+            ApiMethodDescriptor.class,
+            Code.class,
+            Exception.class,
+            FakeStatusCode.class,
+            GaxHttpJsonProperties.class,
+            ImmutableList.class,
+            MockHttpService.class));
+  }
+
+  @Override
+  protected Map<String, VariableExpr> createClassMemberVarExprs(
+      Service service, GapicContext context, TypeStore typeStore) {
+    BiFunction<String, TypeNode, VariableExpr> varExprFn =
+        (name, type) ->
+            VariableExpr.withVariable(Variable.builder().setName(name).setType(type).build());
+    Map<String, TypeNode> fields = new LinkedHashMap<>();
+    fields.put(
+        MOCK_SERVICE_VAR_NAME, FIXED_REST_TYPESTORE.get(MockHttpService.class.getSimpleName()));
+    fields.put(CLIENT_VAR_NAME, typeStore.get(ClassNames.getServiceClientClassName(service)));
+    return fields.entrySet().stream()
+        .collect(Collectors.toMap(e -> e.getKey(), e -> varExprFn.apply(e.getKey(), e.getValue())));
+  }
+
+  @Override
+  protected List<Statement> createClassMemberFieldDecls(
+      Map<String, VariableExpr> classMemberVarExprs) {
+    return classMemberVarExprs.values().stream()
+        .map(
+            v ->
+                ExprStatement.withExpr(
+                    v.toBuilder()
+                        .setIsDecl(true)
+                        .setScope(ScopeNode.PRIVATE)
+                        .setIsStatic(true)
+                        .build()))
+        .collect(Collectors.toList());
+  }
+
+  @Override
+  protected MethodDefinition createStartStaticServerMethod(
+      Service service,
+      GapicContext context,
+      Map<String, VariableExpr> classMemberVarExprs,
+      TypeStore typeStore,
+      String newBuilderMethod) {
+
+    VariableExpr mockServiceVarExpr = classMemberVarExprs.get(MOCK_SERVICE_VAR_NAME);
+    VariableExpr clientVarExpr = classMemberVarExprs.get(CLIENT_VAR_NAME);
+    TypeNode settingsType = typeStore.get(ClassNames.getServiceSettingsClassName(service));
+    TypeNode transportStubType =
+        typeStore.get(getTransportContext().classNames().getTransportServiceStubClassName(service));
+
+    Function<Expr, BiFunction<String, Expr, MethodInvocationExpr>> methodBuilderFn =
+        methodExpr ->
+            (mName, argExpr) ->
+                MethodInvocationExpr.builder()
+                    .setExprReferenceExpr(methodExpr)
+                    .setMethodName(mName)
+                    .setArguments(Arrays.asList(argExpr))
+                    .build();
+
+    Expr initMockServiceExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(mockServiceVarExpr)
+            .setValueExpr(
+                NewObjectExpr.builder()
+                    .setType(mockServiceVarExpr.type())
+                    .setArguments(
+                        MethodInvocationExpr.builder()
+                            .setStaticReferenceType(transportStubType)
+                            .setMethodName("getMethodDescriptors")
+                            .build(),
+                        MethodInvocationExpr.builder()
+                            .setStaticReferenceType(settingsType)
+                            .setMethodName("getDefaultEndpoint")
+                            .build())
+                    .build())
+            .build();
+
+    VariableExpr localSettingsVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setName("settings").setType(settingsType).build());
+
+    Expr settingsBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(settingsType)
+            .setMethodName(newBuilderMethod)
+            .build();
+
+    Expr transportChannelProviderExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(settingsType)
+            .setMethodName("defaultHttpJsonTransportProviderBuilder")
+            .build();
+
+    transportChannelProviderExpr =
+        methodBuilderFn
+            .apply(transportChannelProviderExpr)
+            .apply("setHttpTransport", mockServiceVarExpr);
+
+    transportChannelProviderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(transportChannelProviderExpr)
+            .setMethodName("build")
+            .setReturnType(localSettingsVarExpr.type())
+            .build();
+
+    settingsBuilderExpr =
+        methodBuilderFn
+            .apply(settingsBuilderExpr)
+            .apply("setTransportChannelProvider", transportChannelProviderExpr);
+
+    settingsBuilderExpr =
+        methodBuilderFn
+            .apply(settingsBuilderExpr)
+            .apply(
+                "setCredentialsProvider",
+                MethodInvocationExpr.builder()
+                    .setStaticReferenceType(FIXED_TYPESTORE.get("NoCredentialsProvider"))
+                    .setMethodName("create")
+                    .build());
+    settingsBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(settingsBuilderExpr)
+            .setMethodName("build")
+            .setReturnType(localSettingsVarExpr.type())
+            .build();
+
+    Expr initLocalSettingsExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(localSettingsVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(settingsBuilderExpr)
+            .build();
+
+    Expr initClientExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(clientVarExpr)
+            .setValueExpr(
+                MethodInvocationExpr.builder()
+                    .setStaticReferenceType(
+                        typeStore.get(ClassNames.getServiceClientClassName(service)))
+                    .setMethodName("create")
+                    .setArguments(Arrays.asList(localSettingsVarExpr))
+                    .setReturnType(clientVarExpr.type())
+                    .build())
+            .build();
+
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(AnnotationNode.withType(FIXED_TYPESTORE.get("BeforeClass"))))
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(TypeNode.VOID)
+        .setName("startStaticServer")
+        .setThrowsExceptions(Arrays.asList(FIXED_TYPESTORE.get("IOException")))
+        .setIsStatic(true)
+        .setBody(
+            Arrays.asList(initMockServiceExpr, initLocalSettingsExpr, initClientExpr).stream()
+                .map(e -> ExprStatement.withExpr(e))
+                .collect(Collectors.toList()))
+        .build();
+  }
+
+  @Override
+  protected MethodDefinition createStopServerMethod(
+      Service service, Map<String, VariableExpr> classMemberVarExprs) {
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(AnnotationNode.withType(FIXED_TYPESTORE.get("AfterClass"))))
+        .setScope(ScopeNode.PUBLIC)
+        .setIsStatic(true)
+        .setReturnType(TypeNode.VOID)
+        .setName("stopServer")
+        .setBody(
+            Arrays.asList(
+                ExprStatement.withExpr(
+                    MethodInvocationExpr.builder()
+                        .setExprReferenceExpr(classMemberVarExprs.get(CLIENT_VAR_NAME))
+                        .setMethodName("close")
+                        .build())))
+        .build();
+  }
+
+  @Override
+  protected MethodDefinition createSetUpMethod(
+      Service service, Map<String, VariableExpr> classMemberVarExprs, TypeStore typeStore) {
+
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(AnnotationNode.withType(FIXED_TYPESTORE.get("Before"))))
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(TypeNode.VOID)
+        .setName("setUp")
+        .setBody(Arrays.asList())
+        .build();
+  }
+
+  @Override
+  protected MethodDefinition createTearDownMethod(
+      Service service, Map<String, VariableExpr> classMemberVarExprs) {
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(AnnotationNode.withType(FIXED_TYPESTORE.get("After"))))
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(TypeNode.VOID)
+        .setName("tearDown")
+        .setThrowsExceptions(
+            Arrays.asList(TypeNode.withReference(ConcreteReference.withClazz(Exception.class))))
+        .setBody(
+            Arrays.asList(
+                ExprStatement.withExpr(
+                    MethodInvocationExpr.builder()
+                        .setExprReferenceExpr(classMemberVarExprs.get(MOCK_SERVICE_VAR_NAME))
+                        .setMethodName("reset")
+                        .build())))
+        .build();
+  }
+
+  @Override
+  protected List<Statement> constructRpcTestCheckerLogic(
+      Method method,
+      Service service,
+      boolean isRequestArg,
+      Map<String, VariableExpr> classMemberVarExprs,
+      VariableExpr requestVarExpr,
+      Message requestMessage,
+      List<VariableExpr> argExprs) {
+
+    VariableExpr actualRequestsVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setType(
+                    TypeNode.withReference(
+                        ConcreteReference.builder()
+                            .setClazz(List.class)
+                            .setGenerics(Arrays.asList(TypeNode.STRING.reference()))
+                            .build()))
+                .setName("actualRequests")
+                .build());
+
+    List<Expr> methodExprs = new ArrayList<>();
+    methodExprs.add(
+        AssignmentExpr.builder()
+            .setVariableExpr(actualRequestsVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(
+                MethodInvocationExpr.builder()
+                    .setExprReferenceExpr(classMemberVarExprs.get(getMockServiceVarName(service)))
+                    .setMethodName("getRequestPaths")
+                    .setReturnType(actualRequestsVarExpr.type())
+                    .build())
+            .build());
+
+    methodExprs.add(
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(FIXED_TYPESTORE.get("Assert"))
+            .setMethodName("assertEquals")
+            .setArguments(
+                ValueExpr.withValue(
+                    PrimitiveValue.builder().setType(TypeNode.INT).setValue("1").build()),
+                MethodInvocationExpr.builder()
+                    .setExprReferenceExpr(actualRequestsVarExpr)
+                    .setMethodName("size")
+                    .build())
+            .build());
+
+    List<Statement> methodStatements = new ArrayList<>();
+    methodStatements.addAll(
+        methodExprs.stream().map(ExprStatement::withExpr).collect(Collectors.toList()));
+
+    methodExprs.clear();
+    methodStatements.add(EMPTY_LINE_STATEMENT);
+
+    VariableExpr apiClientHeaderKeyVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder().setType(TypeNode.STRING).setName("apiClientHeaderKey").build());
+
+    AssignmentExpr apiClientHeaderKeyAssignExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(apiClientHeaderKeyVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(
+                MethodInvocationExpr.builder()
+                    .setMethodName("next")
+                    .setReturnType(apiClientHeaderKeyVarExpr.type())
+                    .setExprReferenceExpr(
+                        MethodInvocationExpr.builder()
+                            .setMethodName("iterator")
+                            .setExprReferenceExpr(
+                                MethodInvocationExpr.builder()
+                                    .setMethodName("get")
+                                    .setArguments(
+                                        MethodInvocationExpr.builder()
+                                            .setMethodName("getDefaultApiClientHeaderKey")
+                                            .setStaticReferenceType(
+                                                FIXED_REST_TYPESTORE.get("ApiClientHeaderProvider"))
+                                            .build())
+                                    .setExprReferenceExpr(
+                                        MethodInvocationExpr.builder()
+                                            .setMethodName("getRequestHeaders")
+                                            .setExprReferenceExpr(
+                                                classMemberVarExprs.get(
+                                                    getMockServiceVarName(service)))
+                                            .build())
+                                    .build())
+                            .build())
+                    .build())
+            .build();
+
+    methodExprs.add(apiClientHeaderKeyAssignExpr);
+
+    methodExprs.add(
+        MethodInvocationExpr.builder()
+            .setMethodName("assertTrue")
+            .setStaticReferenceType(FIXED_TYPESTORE.get("Assert"))
+            .setArguments(
+                MethodInvocationExpr.builder()
+                    .setMethodName("matches")
+                    .setExprReferenceExpr(
+                        MethodInvocationExpr.builder()
+                            .setMethodName("matcher")
+                            .setArguments(apiClientHeaderKeyVarExpr)
+                            .setExprReferenceExpr(
+                                MethodInvocationExpr.builder()
+                                    .setMethodName("getDefaultApiClientHeaderPattern")
+                                    .setStaticReferenceType(
+                                        FIXED_REST_TYPESTORE.get("GaxHttpJsonProperties"))
+                                    .build())
+                            .build())
+                    .build())
+            .build());
+
+    methodStatements.addAll(
+        methodExprs.stream().map(ExprStatement::withExpr).collect(Collectors.toList()));
+    methodExprs.clear();
+
+    return methodStatements;
+  }
+
+  @Override
+  protected MethodDefinition createStreamingRpcTestMethod(
+      Service service,
+      Method method,
+      Map<String, VariableExpr> classMemberVarExprs,
+      Map<String, ResourceName> resourceNames,
+      Map<String, Message> messageTypes) {
+    // Add some actual statements once implemented
+    List<Statement> methodStatements = new ArrayList<>();
+
+    String testMethodName = String.format("%sTest", JavaStyle.toLowerCamelCase(method.name()));
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(TEST_ANNOTATION))
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(TypeNode.VOID)
+        .setName(testMethodName)
+        .setThrowsExceptions(Arrays.asList(TypeNode.withExceptionClazz(Exception.class)))
+        .setBody(methodStatements)
+        .build();
+  }
+
+  @Override
+  protected MethodDefinition createRpcExceptionTestMethod(
+      Method method,
+      Service service,
+      List<MethodArgument> methodSignature,
+      int variantIndex,
+      Map<String, VariableExpr> classMemberVarExprs,
+      Map<String, ResourceName> resourceNames,
+      Map<String, Message> messageTypes) {
+    VariableExpr exceptionVarExpr =
+        VariableExpr.withVariable(
+            Variable.builder()
+                .setType(FIXED_REST_TYPESTORE.get("ApiException"))
+                .setName("exception")
+                .build());
+
+    // First two assignment lines.
+    Expr exceptionAssignExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(exceptionVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(
+                MethodInvocationExpr.builder()
+                    .setMethodName("createException")
+                    .setStaticReferenceType(FIXED_REST_TYPESTORE.get("ApiExceptionFactory"))
+                    .setArguments(
+                        NewObjectExpr.withType(FIXED_REST_TYPESTORE.get("Exception")),
+                        MethodInvocationExpr.builder()
+                            .setMethodName("of")
+                            .setStaticReferenceType(FIXED_REST_TYPESTORE.get("FakeStatusCode"))
+                            .setArguments(
+                                EnumRefExpr.builder()
+                                    .setName("INVALID_ARGUMENT")
+                                    .setType(FIXED_REST_TYPESTORE.get("Code"))
+                                    .build())
+                            .build(),
+                        ValueExpr.withValue(
+                            PrimitiveValue.builder()
+                                .setType(TypeNode.BOOLEAN)
+                                .setValue("false")
+                                .build()))
+                    .setReturnType(exceptionVarExpr.type())
+                    .build())
+            .build();
+
+    Expr addExceptionExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(classMemberVarExprs.get(getMockServiceVarName(service)))
+            .setMethodName("addException")
+            .setArguments(exceptionVarExpr)
+            .build();
+
+    // Try-catch block. Build the method call.
+    String exceptionTestMethodName =
+        String.format(
+            "%sExceptionTest%s",
+            JavaStyle.toLowerCamelCase(method.name()), variantIndex > 0 ? variantIndex + 1 : "");
+
+    boolean isStreaming = !method.stream().equals(Method.Stream.NONE);
+    List<Statement> methodBody = new ArrayList<>();
+    methodBody.add(ExprStatement.withExpr(exceptionAssignExpr));
+    methodBody.add(ExprStatement.withExpr(addExceptionExpr));
+    if (isStreaming) {
+      methodBody.addAll(
+          createStreamingRpcExceptionTestStatements(
+              method, classMemberVarExprs, resourceNames, messageTypes));
+    } else {
+      methodBody.addAll(
+          createRpcExceptionTestStatements(
+              method, methodSignature, classMemberVarExprs, resourceNames, messageTypes));
+    }
+
+    return MethodDefinition.builder()
+        .setAnnotations(Arrays.asList(TEST_ANNOTATION))
+        .setScope(ScopeNode.PUBLIC)
+        .setReturnType(TypeNode.VOID)
+        .setName(exceptionTestMethodName)
+        .setThrowsExceptions(Arrays.asList(TypeNode.withExceptionClazz(Exception.class)))
+        .setBody(methodBody)
+        .build();
+  }
+
+  @Override
+  protected List<Statement> createStreamingRpcExceptionTestStatements(
+      Method method,
+      Map<String, VariableExpr> classMemberVarExprs,
+      Map<String, ResourceName> resourceNames,
+      Map<String, Message> messageTypes) {
+    return Collections.emptyList();
+  }
+
+  @Override
+  protected Expr createDefaultValue(
+      MethodArgument methodArg, Map<String, ResourceName> resourceNames) {
+    return DefaultValueComposer.createDefaultValue(methodArg, resourceNames, true);
+  }
+
+  @Override
+  protected List<Statement> createRpcLroExceptionTestCatchBody(
+      VariableExpr exceptionExpr, boolean isStreaming) {
+    return Collections.emptyList();
+  }
+
+  @Override
+  protected String getMockServiceVarName(Service service) {
+    return String.format(MOCK_SERVICE_VAR_NAME);
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceSettingsClassComposer.java
new file mode 100644
index 0000000000..637dea043f
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceSettingsClassComposer.java
@@ -0,0 +1,29 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.gapic.composer.common.AbstractServiceSettingsClassComposer;
+
+public class ServiceSettingsClassComposer extends AbstractServiceSettingsClassComposer {
+  private static final ServiceSettingsClassComposer INSTANCE = new ServiceSettingsClassComposer();
+
+  protected ServiceSettingsClassComposer() {
+    super(RestContext.instance());
+  }
+
+  public static ServiceSettingsClassComposer instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceStubClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceStubClassComposer.java
new file mode 100644
index 0000000000..704fac96b6
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceStubClassComposer.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.gapic.composer.common.AbstractServiceStubClassComposer;
+
+public class ServiceStubClassComposer extends AbstractServiceStubClassComposer {
+  private static final ServiceStubClassComposer INSTANCE = new ServiceStubClassComposer();
+
+  protected ServiceStubClassComposer() {
+    super(RestContext.instance());
+  }
+
+  public static ServiceStubClassComposer instance() {
+    return INSTANCE;
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceStubSettingsClassComposer.java b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceStubSettingsClassComposer.java
new file mode 100644
index 0000000000..b12528ec3f
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/composer/rest/ServiceStubSettingsClassComposer.java
@@ -0,0 +1,87 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.generator.engine.ast.MethodDefinition;
+import com.google.api.generator.engine.ast.MethodInvocationExpr;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.ast.TypeNode;
+import com.google.api.generator.gapic.composer.common.AbstractServiceStubSettingsClassComposer;
+import com.google.api.generator.gapic.composer.store.TypeStore;
+import com.google.api.generator.gapic.model.Service;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+public class ServiceStubSettingsClassComposer extends AbstractServiceStubSettingsClassComposer {
+  private static final ServiceStubSettingsClassComposer INSTANCE =
+      new ServiceStubSettingsClassComposer();
+
+  private static final TypeStore FIXED_REST_TYPESTORE = createStaticTypes();
+
+  public static ServiceStubSettingsClassComposer instance() {
+    return INSTANCE;
+  }
+
+  protected ServiceStubSettingsClassComposer() {
+    super(RestContext.instance());
+  }
+
+  private static TypeStore createStaticTypes() {
+    return new TypeStore(
+        Arrays.asList(
+            GaxHttpJsonProperties.class,
+            HttpJsonTransportChannel.class,
+            InstantiatingHttpJsonChannelProvider.class));
+  }
+
+  @Override
+  protected List<MethodDefinition> createApiClientHeaderProviderBuilderMethods(
+      Service service, TypeStore typeStore) {
+    return Collections.singletonList(
+        createApiClientHeaderProviderBuilderMethod(
+            service,
+            typeStore,
+            "defaultApiClientHeaderProviderBuilder",
+            FIXED_REST_TYPESTORE.get(GaxHttpJsonProperties.class.getSimpleName()),
+            "getHttpJsonTokenName",
+            "getHttpJsonVersion"));
+  }
+
+  @Override
+  public MethodDefinition createDefaultTransportChannelProviderMethod() {
+    TypeNode returnType = FIXED_TYPESTORE.get("TransportChannelProvider");
+    MethodInvocationExpr transportProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("defaultHttpJsonTransportProviderBuilder")
+            .build();
+    transportProviderBuilderExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(transportProviderBuilderExpr)
+            .setMethodName("build")
+            .setReturnType(returnType)
+            .build();
+    return MethodDefinition.builder()
+        .setScope(ScopeNode.PUBLIC)
+        .setIsStatic(true)
+        .setReturnType(returnType)
+        .setName("defaultTransportChannelProvider")
+        .setReturnExpr(transportProviderBuilderExpr)
+        .build();
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposer.java b/src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposer.java
index a9403b54a3..5572bde8e3 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposer.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposer.java
@@ -59,6 +59,7 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
@@ -70,6 +71,7 @@ public static String composeClassHeaderMethodSampleCode(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     // Use the first pure unary RPC method's sample code as showcase, if no such method exists, use
     // the first method in the service's methods list.
     Method method =
@@ -232,6 +234,7 @@ public static String composeRpcMethodHeaderSampleCode(
       List<MethodArgument> arguments,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     VariableExpr clientVarExpr =
         VariableExpr.withVariable(
             Variable.builder()
@@ -278,6 +281,7 @@ public static String composeRpcDefaultMethodHeaderSampleCode(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     VariableExpr clientVarExpr =
         VariableExpr.withVariable(
             Variable.builder()
@@ -336,6 +340,7 @@ public static String composeLroCallableMethodHeaderSampleCode(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     VariableExpr clientVarExpr =
         VariableExpr.withVariable(
             Variable.builder()
@@ -448,6 +453,7 @@ public static String composePagedCallableMethodHeaderSampleCode(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     VariableExpr clientVarExpr =
         VariableExpr.withVariable(
             Variable.builder()
@@ -477,7 +483,7 @@ public static String composePagedCallableMethodHeaderSampleCode(
 
     // Find the repeated field.
     Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
-    Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
+    Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
     Preconditions.checkNotNull(
         repeatedPagedResultsField,
         String.format(
@@ -567,6 +573,7 @@ public static String composeRegularCallableMethodHeaderSampleCode(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     VariableExpr clientVarExpr =
         VariableExpr.withVariable(
             Variable.builder()
@@ -616,6 +623,7 @@ public static String composeStreamCallableMethodHeaderSampleCode(
       TypeNode clientType,
       Map<String, ResourceName> resourceNames,
       Map<String, Message> messageTypes) {
+    resourceNames = sortAlphabetically(resourceNames);
     VariableExpr clientVarExpr =
         VariableExpr.withVariable(
             Variable.builder()
@@ -708,7 +716,7 @@ private static List<Statement> composeUnaryPagedRpcMethodBodyStatements(
         "Output message %s not found, keys: ",
         method.outputType().reference().fullName(),
         messageTypes.keySet().toString());
-    Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
+    Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
     Preconditions.checkNotNull(
         repeatedPagedResultsField,
         String.format(
@@ -1134,7 +1142,7 @@ private static List<Statement> composePagedCallableBodyStatements(
       Map<String, Message> messageTypes) {
     // Find the repeated field.
     Message methodOutputMessage = messageTypes.get(method.outputType().reference().fullName());
-    Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapFirstRepeatedField();
+    Field repeatedPagedResultsField = methodOutputMessage.findAndUnwrapPaginatedRepeatedField();
     Preconditions.checkNotNull(
         repeatedPagedResultsField,
         String.format(
@@ -1302,7 +1310,7 @@ private static List<Expr> createRpcMethodArgumentDefaultValueExprs(
         .map(
             arg ->
                 !isStringTypedResourceName(arg, resourceNames)
-                    ? DefaultValueComposer.createDefaultValue(arg, resourceNames)
+                    ? DefaultValueComposer.createDefaultValue(arg, resourceNames, false)
                     : stringResourceNameDefaultValueExpr.apply(arg))
         .collect(Collectors.toList());
   }
@@ -1349,4 +1357,16 @@ private static boolean isProtoEmptyType(TypeNode type) {
     return type.reference().pakkage().equals("com.google.protobuf")
         && type.reference().name().equals("Empty");
   }
+
+  /**
+   * Returns the same "resource type name" to "resource name" key-value map as given, but sorted in
+   * alphabetical order. This prevents resource name flip-flopping between executions on the various
+   * machines used for client library publication.
+   */
+  private static TreeMap<String, ResourceName> sortAlphabetically(
+      Map<String, ResourceName> unsorted) {
+    // This simple wrapper is not redundant because it hides implementation details from the
+    // callers.
+    return new TreeMap<>(unsorted);
+  }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/composer/store/TypeStore.java b/src/main/java/com/google/api/generator/gapic/composer/store/TypeStore.java
index 061c42a67c..4113c3446b 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/store/TypeStore.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/store/TypeStore.java
@@ -28,7 +28,11 @@ public class TypeStore {
 
   public TypeStore() {}
 
-  public TypeStore(List<Class> concreteClasses) {
+  public TypeStore(List<Class<?>> concreteClasses) {
+    putConcreteClassses(concreteClasses);
+  }
+
+  private void putConcreteClassses(List<Class<?>> concreteClasses) {
     store.putAll(
         concreteClasses.stream()
             .collect(
@@ -67,6 +71,10 @@ public void put(
                 .build()));
   }
 
+  public void putAll(List<Class<?>> concreteClasses) {
+    putConcreteClassses(concreteClasses);
+  }
+
   public void putAll(
       String pakkage,
       List<String> typeNames,
diff --git a/src/main/java/com/google/api/generator/gapic/composer/utils/ClassNames.java b/src/main/java/com/google/api/generator/gapic/composer/utils/ClassNames.java
index f1abb45a4c..c0b717fc0a 100644
--- a/src/main/java/com/google/api/generator/gapic/composer/utils/ClassNames.java
+++ b/src/main/java/com/google/api/generator/gapic/composer/utils/ClassNames.java
@@ -15,6 +15,9 @@
 package com.google.api.generator.gapic.composer.utils;
 
 import com.google.api.generator.gapic.model.Service;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
 
 /** Provides Gapic class names. */
 public class ClassNames {
@@ -23,6 +26,7 @@ public class ClassNames {
   private static final String MOCK_SERVICE_IMPL_CLASS_NAME_PATTERN = "Mock%sImpl";
   private static final String SERVICE_CLIENT_CLASS_NAME_PATTERN = "%sClient";
   private static final String SERVICE_CLIENT_TEST_CLASS_NAME_PATTERN = "%sClientTest";
+  private static final String SERVICE_CLIENT_TRANSPORT_TEST_CLASS_NAME_PATTERN = "%sClient%sTest";
   private static final String SERVICE_SETTINGS_CLASS_NAME_PATTERN = "%sSettings";
   private static final String SERVICE_STUB_SETTINGS_CLASS_NAME_PATTERN = "%sStubSettings";
   private static final String SERVICE_STUB_CLASS_NAME_PATTERN = "%sStub";
@@ -30,10 +34,10 @@ public class ClassNames {
   private static final String TRANSPORT_SERVICE_CALLABLE_FACTORY_CLASS_NAME_PATTERN =
       "%s%sCallableFactory";
 
-  private final String transportPrefix;
+  private final List<String> transportPrefixes;
 
-  public ClassNames(String transportPrefix) {
-    this.transportPrefix = transportPrefix;
+  public ClassNames(String... transportPrefixes) {
+    this.transportPrefixes = Arrays.asList(transportPrefixes);
   }
 
   public static String getServiceClientClassName(Service service) {
@@ -59,23 +63,50 @@ public static String getServiceStubClassName(Service service) {
   }
 
   public String getTransportServiceCallableFactoryClassName(Service service) {
-    return String.format(
-        TRANSPORT_SERVICE_CALLABLE_FACTORY_CLASS_NAME_PATTERN,
-        transportPrefix,
-        monolithBackwardsCompatibleName(service.name()));
+    return getTransportServiceCallableFactoryClassNames(service).get(0);
+  }
+
+  public List<String> getTransportServiceCallableFactoryClassNames(Service service) {
+    return transportPrefixes.stream()
+        .map(
+            prefix ->
+                String.format(
+                    TRANSPORT_SERVICE_CALLABLE_FACTORY_CLASS_NAME_PATTERN,
+                    prefix,
+                    monolithBackwardsCompatibleName(service.name())))
+        .collect(Collectors.toList());
   }
 
   public String getTransportServiceStubClassName(Service service) {
-    return String.format(
-        TRANSPORT_SERVICE_STUB_CLASS_NAME_PATTERN,
-        transportPrefix,
-        monolithBackwardsCompatibleName(service.name()));
+    return getTransportServiceStubClassNames(service).get(0);
+  }
+
+  public List<String> getTransportServiceStubClassNames(Service service) {
+    return transportPrefixes.stream()
+        .map(
+            prefix ->
+                String.format(
+                    TRANSPORT_SERVICE_STUB_CLASS_NAME_PATTERN,
+                    prefix,
+                    monolithBackwardsCompatibleName(service.name())))
+        .collect(Collectors.toList());
   }
 
   public static String getServiceClientTestClassName(Service service) {
     return String.format(SERVICE_CLIENT_TEST_CLASS_NAME_PATTERN, service.overriddenName());
   }
 
+  public List<String> getServiceClientTestClassNames(Service service) {
+    return transportPrefixes.stream()
+        .map(
+            prefix ->
+                String.format(
+                    SERVICE_CLIENT_TRANSPORT_TEST_CLASS_NAME_PATTERN,
+                    service.overriddenName(),
+                    prefix))
+        .collect(Collectors.toList());
+  }
+
   public static String getMockServiceClassName(Service service) {
     return String.format(MOCK_SERVICE_CLASS_NAME_PATTERN, service.name());
   }
diff --git a/src/main/java/com/google/api/generator/gapic/model/Field.java b/src/main/java/com/google/api/generator/gapic/model/Field.java
index e178e417e6..a5ec9caacb 100644
--- a/src/main/java/com/google/api/generator/gapic/model/Field.java
+++ b/src/main/java/com/google/api/generator/gapic/model/Field.java
@@ -17,12 +17,19 @@
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.auto.value.AutoValue;
 import java.util.Objects;
+import java.util.Optional;
 import javax.annotation.Nullable;
 
 @AutoValue
 public abstract class Field {
+  // The field's canonical name, potentially post-processed by conflict resolution logic.
   public abstract String name();
 
+  // The field's name as it appeared in the protobuf.
+  // Not equal to name() only when there is a field name conflict, as per protoc's conflict
+  // resolution behavior. For more context, please see the invocation site of the setter method.
+  public abstract String originalName();
+
   public abstract TypeNode type();
 
   public abstract boolean isMessage();
@@ -35,12 +42,18 @@ public abstract class Field {
 
   public abstract boolean isContainedInOneof();
 
+  public abstract boolean isProto3Optional();
+
   @Nullable
   public abstract ResourceReference resourceReference();
 
   @Nullable
   public abstract String description();
 
+  public boolean hasFieldNameConflict() {
+    return !name().equals(originalName());
+  }
+
   public boolean hasDescription() {
     return description() != null;
   }
@@ -57,12 +70,14 @@ public boolean equals(Object o) {
 
     Field other = (Field) o;
     return name().equals(other.name())
+        && originalName().equals(other.originalName())
         && type().equals(other.type())
         && isMessage() == other.isMessage()
         && isEnum() == other.isEnum()
         && isRepeated() == other.isRepeated()
         && isMap() == other.isMap()
         && isContainedInOneof() == other.isContainedInOneof()
+        && isProto3Optional() == other.isProto3Optional()
         && Objects.equals(resourceReference(), other.resourceReference())
         && Objects.equals(description(), other.description());
   }
@@ -70,12 +85,14 @@ && isContainedInOneof() == other.isContainedInOneof()
   @Override
   public int hashCode() {
     return 17 * name().hashCode()
+        + 31 * originalName().hashCode()
         + 19 * type().hashCode()
         + (isMessage() ? 1 : 0) * 23
         + (isEnum() ? 1 : 0) * 29
         + (isRepeated() ? 1 : 0) * 31
         + (isMap() ? 1 : 0) * 37
         + (isContainedInOneof() ? 1 : 0) * 41
+        + (isProto3Optional() ? 1 : 0) * 43
         + (resourceReference() == null ? 0 : resourceReference().hashCode())
         + (description() == null ? 0 : description().hashCode());
   }
@@ -88,13 +105,16 @@ public static Builder builder() {
         .setIsEnum(false)
         .setIsRepeated(false)
         .setIsMap(false)
-        .setIsContainedInOneof(false);
+        .setIsContainedInOneof(false)
+        .setIsProto3Optional(false);
   }
 
   @AutoValue.Builder
   public abstract static class Builder {
     public abstract Builder setName(String name);
 
+    public abstract Builder setOriginalName(String originalName);
+
     public abstract Builder setType(TypeNode type);
 
     public abstract Builder setIsMessage(boolean isMessage);
@@ -107,10 +127,24 @@ public abstract static class Builder {
 
     public abstract Builder setIsContainedInOneof(boolean isContainedInOneof);
 
+    public abstract Builder setIsProto3Optional(boolean isProto3Optional);
+
     public abstract Builder setResourceReference(ResourceReference resourceReference);
 
     public abstract Builder setDescription(String description);
 
-    public abstract Field build();
+    // Private accessors.
+    abstract String name();
+
+    abstract Optional<String> originalName();
+
+    abstract Field autoBuild();
+
+    public Field build() {
+      if (!originalName().isPresent()) {
+        setOriginalName(name());
+      }
+      return autoBuild();
+    }
   }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/model/HttpBindings.java b/src/main/java/com/google/api/generator/gapic/model/HttpBindings.java
new file mode 100644
index 0000000000..171f6b1bf7
--- /dev/null
+++ b/src/main/java/com/google/api/generator/gapic/model/HttpBindings.java
@@ -0,0 +1,109 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.model;
+
+import com.google.api.generator.gapic.utils.JavaStyle;
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableSet;
+import java.util.Set;
+
+@AutoValue
+public abstract class HttpBindings {
+  public enum HttpVerb {
+    GET,
+    PUT,
+    POST,
+    DELETE,
+    PATCH,
+  }
+
+  @AutoValue
+  public abstract static class HttpBinding implements Comparable<HttpBinding> {
+    public abstract String name();
+
+    public abstract boolean isOptional();
+
+    public static HttpBinding create(String name, boolean isOptional) {
+      return new AutoValue_HttpBindings_HttpBinding(name, isOptional);
+    }
+
+    // Do not forget to keep it in sync with equals() implementation.
+    @Override
+    public int compareTo(HttpBinding o) {
+      int res = name().compareTo(o.name());
+      return res == 0 ? Boolean.compare(isOptional(), o.isOptional()) : res;
+    }
+  }
+
+  public abstract HttpVerb httpVerb();
+
+  public abstract String pattern();
+
+  public abstract Set<HttpBinding> pathParameters();
+
+  public abstract Set<HttpBinding> queryParameters();
+
+  public abstract Set<HttpBinding> bodyParameters();
+
+  public abstract boolean isAsteriskBody();
+
+  public static HttpBindings.Builder builder() {
+    return new AutoValue_HttpBindings.Builder()
+        .setPathParameters(ImmutableSet.of())
+        .setQueryParameters(ImmutableSet.of())
+        .setBodyParameters(ImmutableSet.of());
+  }
+
+  // Protobuf fields and template patterns follow snake_case style. When translated into actual Java
+  // class fields and URL respectively, those must be converted to lowerCamelCase.
+  // For example:
+  //   in .proto file: "/global/instanceTemplates/{instance_template=*}"
+  //   in .java file:  "/global/instanceTemplates/{instanceTemplate=*}"
+  public String patternLowerCamel() {
+    String lowerCamelPattern = pattern();
+    for (HttpBinding pathParam : pathParameters()) {
+      lowerCamelPattern =
+          lowerCamelPattern.replaceAll(
+              "\\{" + pathParam.name(), "{" + JavaStyle.toLowerCamelCase(pathParam.name()));
+    }
+    return lowerCamelPattern;
+  }
+
+  @AutoValue.Builder
+  public abstract static class Builder {
+    public abstract HttpBindings.Builder setHttpVerb(HttpVerb httpVerb);
+
+    public abstract HttpBindings.Builder setPattern(String pattern);
+
+    abstract String pattern();
+
+    public abstract HttpBindings.Builder setPathParameters(Set<HttpBinding> pathParameters);
+
+    public abstract HttpBindings.Builder setQueryParameters(Set<HttpBinding> queryParameters);
+
+    public abstract HttpBindings.Builder setBodyParameters(Set<HttpBinding> bodyParameters);
+
+    public abstract HttpBindings.Builder setIsAsteriskBody(boolean asteriskBody);
+
+    public abstract HttpBindings autoBuild();
+
+    public HttpBindings build() {
+      if ("".equals(pattern())) {
+        throw new IllegalArgumentException("pattern cannot be empty");
+      }
+      return autoBuild();
+    }
+  }
+}
diff --git a/src/main/java/com/google/api/generator/gapic/model/Message.java b/src/main/java/com/google/api/generator/gapic/model/Message.java
index ad1efa285a..c58e62582e 100644
--- a/src/main/java/com/google/api/generator/gapic/model/Message.java
+++ b/src/main/java/com/google/api/generator/gapic/model/Message.java
@@ -14,11 +14,13 @@
 
 package com.google.api.generator.gapic.model;
 
+import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.Reference;
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.auto.value.AutoValue;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -71,7 +73,22 @@ public boolean hasResource() {
 
   /** Returns the first list repeated field in a message, unwrapped from its list type. */
   @Nullable
-  public Field findAndUnwrapFirstRepeatedField() {
+  public Field findAndUnwrapPaginatedRepeatedField() {
+    for (Field field : fields()) {
+      if (field.isMap()) {
+        List<Reference> repeatedGenericMapRefs = field.type().reference().generics();
+
+        TypeNode paginatedType =
+            TypeNode.withReference(
+                ConcreteReference.builder()
+                    .setClazz(Map.Entry.class)
+                    .setGenerics(
+                        Arrays.asList(repeatedGenericMapRefs.get(0), repeatedGenericMapRefs.get(1)))
+                    .build());
+
+        return field.toBuilder().setType(paginatedType).build();
+      }
+    }
     for (Field field : fields()) {
       if (field.isRepeated() && !field.isMap()) {
         Reference repeatedGenericRef = field.type().reference().generics().get(0);
@@ -123,11 +140,14 @@ public Builder setEnumValues(List<String> names, List<Integer> numbers) {
     public Message build() {
       Message message = autoBuild();
       if (!message.fields().isEmpty()) {
-        message =
-            message
-                .toBuilder()
-                .setFieldMap(fields().stream().collect(Collectors.toMap(f -> f.name(), f -> f)))
-                .autoBuild();
+        Map<String, Field> fieldMap =
+            fields().stream().collect(Collectors.toMap(f -> f.name(), f -> f));
+        // Handles string occurrences of a field's original name in a protobuf, such as
+        // in the method signature annotaiton.
+        fields().stream()
+            .filter(f -> f.hasFieldNameConflict())
+            .forEach(f -> fieldMap.put(f.originalName(), f));
+        message = message.toBuilder().setFieldMap(fieldMap).autoBuild();
       }
       return message;
     }
diff --git a/src/main/java/com/google/api/generator/gapic/model/Method.java b/src/main/java/com/google/api/generator/gapic/model/Method.java
index df5a9aa668..56a1403098 100644
--- a/src/main/java/com/google/api/generator/gapic/model/Method.java
+++ b/src/main/java/com/google/api/generator/gapic/model/Method.java
@@ -39,7 +39,12 @@ public enum Stream {
 
   public abstract boolean isBatching();
 
-  public abstract boolean isPaged();
+  public boolean isPaged() {
+    return pageSizeFieldName() != null;
+  }
+
+  @Nullable
+  public abstract String pageSizeFieldName();
 
   public abstract boolean isDeprecated();
 
@@ -53,9 +58,9 @@ public enum Stream {
   @Nullable
   public abstract String mixedInApiName();
 
-  // TODO(miraleung): May need to change this to MethodArgument, Field, or some new struct
   // HttpBinding pending dotted reference support.
-  public abstract List<String> httpBindings();
+  @Nullable
+  public abstract HttpBindings httpBindings();
 
   // Example from Expand in echo.proto: Thet TypeNodes that map to
   // [["content", "error"], ["content", "error", "info"]].
@@ -70,7 +75,7 @@ public boolean hasDescription() {
   }
 
   public boolean hasHttpBindings() {
-    return !httpBindings().isEmpty();
+    return httpBindings() != null && !httpBindings().pathParameters().isEmpty();
   }
 
   public boolean isMixin() {
@@ -83,9 +88,7 @@ public static Builder builder() {
     return new AutoValue_Method.Builder()
         .setStream(Stream.NONE)
         .setMethodSignatures(ImmutableList.of())
-        .setHttpBindings(ImmutableList.of())
         .setIsBatching(false)
-        .setIsPaged(false)
         .setIsDeprecated(false);
   }
 
@@ -118,13 +121,13 @@ public abstract static class Builder {
 
     public abstract Builder setMixedInApiName(String mixedInApiName);
 
-    public abstract Builder setHttpBindings(List<String> httpBindings);
+    public abstract Builder setHttpBindings(HttpBindings httpBindings);
 
     public abstract Builder setMethodSignatures(List<List<MethodArgument>> methodSignature);
 
     public abstract Builder setIsBatching(boolean isBatching);
 
-    public abstract Builder setIsPaged(boolean isPaged);
+    public abstract Builder setPageSizeFieldName(String pagedFieldName);
 
     public abstract Builder setIsDeprecated(boolean isDeprecated);
 
diff --git a/src/main/java/com/google/api/generator/gapic/model/Service.java b/src/main/java/com/google/api/generator/gapic/model/Service.java
index f21125fb54..2ce5c09d2e 100644
--- a/src/main/java/com/google/api/generator/gapic/model/Service.java
+++ b/src/main/java/com/google/api/generator/gapic/model/Service.java
@@ -49,6 +49,15 @@ public boolean hasDescription() {
     return !Strings.isNullOrEmpty(description());
   }
 
+  public boolean hasLroMethods() {
+    for (Method method : methods()) {
+      if (method.hasLro()) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   public abstract Builder toBuilder();
 
   public static Builder builder() {
diff --git a/src/main/java/com/google/api/generator/gapic/model/Transport.java b/src/main/java/com/google/api/generator/gapic/model/Transport.java
index aeb7b9361c..ae7820c8ed 100644
--- a/src/main/java/com/google/api/generator/gapic/model/Transport.java
+++ b/src/main/java/com/google/api/generator/gapic/model/Transport.java
@@ -17,8 +17,6 @@
 public enum Transport {
   REST,
   GRPC,
-  // Never used in the context as is, must be split into two contexts (REST and GRPC respectively)
-  // instead.
   GRPC_REST;
 
   /**
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParser.java
index 79a1c9817d..f681399342 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParser.java
@@ -20,6 +20,7 @@
 import com.google.common.base.Strings;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -69,7 +70,9 @@ static Optional<List<GapicBatchingSettings>> parse(String gapicYamlConfigFilePat
     String fileContents = null;
 
     try {
-      fileContents = new String(Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)));
+      fileContents =
+          new String(
+              Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)), StandardCharsets.UTF_8);
     } catch (IOException e) {
       return Optional.empty();
     }
@@ -104,7 +107,7 @@ private static Optional<List<GapicBatchingSettings>> parseFromMap(Map<String, Ob
             batchingOuterYamlConfig.containsKey(YAML_KEY_DESCRIPTOR),
             String.format(
                 "%s key expected but not found for method %s",
-                YAML_KEY_DESCRIPTOR, (String) methodYamlConfig.get(YAML_KEY_NAME)));
+                YAML_KEY_DESCRIPTOR, methodYamlConfig.get(YAML_KEY_NAME)));
 
         // Parse the threshold values first.
         Map<String, Object> batchingYamlConfig =
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParser.java
index 6836b3002a..e1cad0ef97 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParser.java
@@ -19,6 +19,7 @@
 import com.google.common.base.Strings;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Map;
@@ -48,7 +49,9 @@ static Optional<GapicLanguageSettings> parse(String gapicYamlConfigFilePath) {
     String fileContents = null;
 
     try {
-      fileContents = new String(Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)));
+      fileContents =
+          new String(
+              Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)), StandardCharsets.UTF_8);
     } catch (IOException e) {
       return Optional.empty();
     }
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParser.java
index ff0cf7e462..b30e93791b 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParser.java
@@ -19,6 +19,7 @@
 import com.google.common.base.Strings;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -56,7 +57,9 @@ static Optional<List<GapicLroRetrySettings>> parse(String gapicYamlConfigFilePat
     String fileContents = null;
 
     try {
-      fileContents = new String(Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)));
+      fileContents =
+          new String(
+              Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)), StandardCharsets.UTF_8);
     } catch (IOException e) {
       return Optional.empty();
     }
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/HttpRuleParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/HttpRuleParser.java
index 10c9b1b071..36828206d3 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/HttpRuleParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/HttpRuleParser.java
@@ -18,16 +18,18 @@
 import com.google.api.HttpRule;
 import com.google.api.HttpRule.PatternCase;
 import com.google.api.generator.gapic.model.Field;
+import com.google.api.generator.gapic.model.HttpBindings;
+import com.google.api.generator.gapic.model.HttpBindings.HttpBinding;
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.pathtemplate.PathTemplate;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSortedSet;
+import com.google.common.collect.Sets;
 import com.google.protobuf.DescriptorProtos.MethodOptions;
 import com.google.protobuf.Descriptors.MethodDescriptor;
-import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashSet;
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -36,11 +38,11 @@
 public class HttpRuleParser {
   private static final String ASTERISK = "*";
 
-  public static Optional<List<String>> parseHttpBindings(
+  public static HttpBindings parse(
       MethodDescriptor protoMethod, Message inputMessage, Map<String, Message> messageTypes) {
     MethodOptions methodOptions = protoMethod.getOptions();
     if (!methodOptions.hasExtension(AnnotationsProto.http)) {
-      return Optional.empty();
+      return null;
     }
 
     HttpRule httpRule = methodOptions.getExtension(AnnotationsProto.http);
@@ -53,86 +55,126 @@ public static Optional<List<String>> parseHttpBindings(
     return parseHttpRuleHelper(httpRule, Optional.of(inputMessage), messageTypes);
   }
 
-  public static Optional<List<String>> parseHttpRule(HttpRule httpRule) {
+  public static HttpBindings parseHttpRule(HttpRule httpRule) {
     return parseHttpRuleHelper(httpRule, Optional.empty(), Collections.emptyMap());
   }
 
-  private static Optional<List<String>> parseHttpRuleHelper(
+  private static HttpBindings parseHttpRuleHelper(
       HttpRule httpRule, Optional<Message> inputMessageOpt, Map<String, Message> messageTypes) {
     // Get pattern.
-    Set<String> uniqueBindings = getHttpVerbPattern(httpRule);
-    if (uniqueBindings.isEmpty()) {
-      return Optional.empty();
-    }
-
+    String pattern = getHttpVerbPattern(httpRule);
+    ImmutableSet.Builder<String> bindingsBuilder = getPatternBindings(pattern);
     if (httpRule.getAdditionalBindingsCount() > 0) {
       for (HttpRule additionalRule : httpRule.getAdditionalBindingsList()) {
-        uniqueBindings.addAll(getHttpVerbPattern(additionalRule));
+        // TODO: save additional bindings path in HttpRuleBindings
+        bindingsBuilder.addAll(getPatternBindings(getHttpVerbPattern(additionalRule)).build());
       }
     }
 
-    List<String> bindings = new ArrayList<>(uniqueBindings);
-    Collections.sort(bindings);
+    Set<String> pathParamNames = bindingsBuilder.build();
+
+    // TODO: support nested message fields bindings
+    String body = httpRule.getBody();
+    Set<String> bodyParamNames;
+    Set<String> queryParamNames;
+    if (!inputMessageOpt.isPresent()) {
+      // Must be a mixin, do not support full HttpRuleBindings for now
+      bodyParamNames = ImmutableSet.of();
+      queryParamNames = ImmutableSet.of();
+    } else if (Strings.isNullOrEmpty(body)) {
+      bodyParamNames = ImmutableSet.of();
+      queryParamNames = Sets.difference(inputMessageOpt.get().fieldMap().keySet(), pathParamNames);
+    } else if (body.equals(ASTERISK)) {
+      bodyParamNames = Sets.difference(inputMessageOpt.get().fieldMap().keySet(), pathParamNames);
+      queryParamNames = ImmutableSet.of();
+    } else {
+      bodyParamNames = ImmutableSet.of(body);
+      Set<String> bodyBinidngsUnion = Sets.union(bodyParamNames, pathParamNames);
+      queryParamNames =
+          Sets.difference(inputMessageOpt.get().fieldMap().keySet(), bodyBinidngsUnion);
+    }
 
-    // Binding validation.
-    for (String binding : bindings) {
-      // Handle foo.bar cases by descending into the subfields.
-      String[] descendantBindings = binding.split("\\.");
-      Optional<Message> containingMessageOpt = inputMessageOpt;
-      for (int i = 0; i < descendantBindings.length; i++) {
-        String subField = descendantBindings[i];
-        if (!containingMessageOpt.isPresent()) {
-          continue;
-        }
+    Message message = inputMessageOpt.orElse(null);
+    return HttpBindings.builder()
+        .setHttpVerb(HttpBindings.HttpVerb.valueOf(httpRule.getPatternCase().toString()))
+        .setPattern(pattern)
+        .setPathParameters(
+            validateAndConstructHttpBindings(pathParamNames, message, messageTypes, true))
+        .setQueryParameters(
+            validateAndConstructHttpBindings(queryParamNames, message, messageTypes, false))
+        .setBodyParameters(
+            validateAndConstructHttpBindings(bodyParamNames, message, messageTypes, false))
+        .setIsAsteriskBody(body.equals(ASTERISK))
+        .build();
+  }
 
-        if (i < descendantBindings.length - 1) {
-          Field field = containingMessageOpt.get().fieldMap().get(subField);
-          containingMessageOpt = Optional.of(messageTypes.get(field.type().reference().fullName()));
+  private static Set<HttpBinding> validateAndConstructHttpBindings(
+      Set<String> paramNames,
+      Message inputMessage,
+      Map<String, Message> messageTypes,
+      boolean isPath) {
+    ImmutableSortedSet.Builder<HttpBinding> httpBindings = ImmutableSortedSet.naturalOrder();
+    for (String paramName : paramNames) {
+      // Handle foo.bar cases by descending into the subfields.
+      String[] subFields = paramName.split("\\.");
+      if (inputMessage == null) {
+        httpBindings.add(HttpBinding.create(paramName, false));
+        continue;
+      }
+      Message nestedMessage = inputMessage;
+      for (int i = 0; i < subFields.length; i++) {
+        String subFieldName = subFields[i];
+        if (i < subFields.length - 1) {
+          Field field = nestedMessage.fieldMap().get(subFieldName);
+          nestedMessage = messageTypes.get(field.type().reference().fullName());
           Preconditions.checkNotNull(
-              containingMessageOpt.get(),
+              nestedMessage,
               String.format(
                   "No containing message found for field %s with type %s",
                   field.name(), field.type().reference().simpleName()));
+
         } else {
-          checkHttpFieldIsValid(subField, containingMessageOpt.get(), false);
+          if (isPath) {
+            checkHttpFieldIsValid(subFieldName, nestedMessage, !isPath);
+          }
+          Field field = nestedMessage.fieldMap().get(subFieldName);
+          httpBindings.add(HttpBinding.create(paramName, field.isProto3Optional()));
         }
       }
     }
-
-    return Optional.of(bindings);
+    return httpBindings.build();
   }
 
-  private static Set<String> getHttpVerbPattern(HttpRule httpRule) {
-    String pattern = null;
-    // Assign a temp variable to prevent the formatter from removing the import.
+  private static String getHttpVerbPattern(HttpRule httpRule) {
     PatternCase patternCase = httpRule.getPatternCase();
     switch (patternCase) {
       case GET:
-        pattern = httpRule.getGet();
-        break;
+        return httpRule.getGet();
       case PUT:
-        pattern = httpRule.getPut();
-        break;
+        return httpRule.getPut();
       case POST:
-        pattern = httpRule.getPost();
-        break;
+        return httpRule.getPost();
       case DELETE:
-        pattern = httpRule.getDelete();
-        break;
+        return httpRule.getDelete();
       case PATCH:
-        pattern = httpRule.getPatch();
-        break;
+        return httpRule.getPatch();
       case CUSTOM: // Invalid pattern.
         // Fall through.
       default:
-        return Collections.emptySet();
+        return "";
+    }
+  }
+
+  private static ImmutableSortedSet.Builder<String> getPatternBindings(String pattern) {
+    ImmutableSortedSet.Builder<String> bindings = ImmutableSortedSet.naturalOrder();
+    if (pattern.isEmpty()) {
+      return bindings;
     }
 
     PathTemplate template = PathTemplate.create(pattern);
-    Set<String> bindings =
-        new HashSet<String>(
-            // Filter out any unbound variable like "$0, $1, etc.
-            template.vars().stream().filter(s -> !s.contains("$")).collect(Collectors.toList()));
+    // Filter out any unbound variable like "$0, $1, etc.
+    bindings.addAll(
+        template.vars().stream().filter(s -> !s.contains("$")).collect(Collectors.toSet()));
     return bindings;
   }
 
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/MethodSignatureParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/MethodSignatureParser.java
index 4d7259790a..9ca9825def 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/MethodSignatureParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/MethodSignatureParser.java
@@ -284,15 +284,4 @@ private static Map<TypeNode, Field> parseTypeFromArgumentName(
         argumentFieldPathAcc,
         outputArgResourceNames);
   }
-
-  private static Map<String, ResourceName> createPatternResourceNameMap(
-      Map<String, ResourceName> resourceNames) {
-    Map<String, ResourceName> patternsToResourceNames = new HashMap<>();
-    for (ResourceName resourceName : resourceNames.values()) {
-      for (String pattern : resourceName.patterns()) {
-        patternsToResourceNames.put(pattern, resourceName);
-      }
-    }
-    return patternsToResourceNames;
-  }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/Parser.java b/src/main/java/com/google/api/generator/gapic/protoparser/Parser.java
index a088e8ae46..8fd376b7e0 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/Parser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/Parser.java
@@ -26,6 +26,7 @@
 import com.google.api.generator.gapic.model.GapicLanguageSettings;
 import com.google.api.generator.gapic.model.GapicLroRetrySettings;
 import com.google.api.generator.gapic.model.GapicServiceConfig;
+import com.google.api.generator.gapic.model.HttpBindings;
 import com.google.api.generator.gapic.model.LongrunningOperation;
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.Method;
@@ -87,6 +88,9 @@ public class Parser {
           "google.iam.v1.IAMPolicy",
           "google.longrunning.Operations",
           "google.cloud.location.Locations");
+  // These must be kept in sync with the above protos' java_package options.
+  private static final Set<String> MIXIN_JAVA_PACKAGE_ALLOWLIST =
+      ImmutableSet.of("com.google.iam.v1", "com.google.longrunning", "com.google.cloud.location");
 
   // Allow other parsers to access this.
   protected static final SourceCodeInfoParser SOURCE_CODE_INFO_PARSER = new SourceCodeInfoParser();
@@ -106,12 +110,13 @@ public static GapicContext parse(CodeGeneratorRequest request) {
         GapicLroRetrySettingsParser.parse(gapicYamlConfigPathOpt);
     Optional<GapicLanguageSettings> languageSettingsOpt =
         GapicLanguageSettingsParser.parse(gapicYamlConfigPathOpt);
+    Optional<String> transportOpt = PluginArgumentParser.parseTransport(request);
 
     boolean willGenerateMetadata = PluginArgumentParser.hasMetadataFlag(request);
 
     Optional<String> serviceConfigPathOpt = PluginArgumentParser.parseJsonConfigPath(request);
-    String serviceConfigPath = serviceConfigPathOpt.isPresent() ? serviceConfigPathOpt.get() : null;
-    Optional<GapicServiceConfig> serviceConfigOpt = ServiceConfigParser.parse(serviceConfigPath);
+    Optional<GapicServiceConfig> serviceConfigOpt =
+        ServiceConfigParser.parse(serviceConfigPathOpt.orElse(null));
     if (serviceConfigOpt.isPresent()) {
       GapicServiceConfig serviceConfig = serviceConfigOpt.get();
       serviceConfig.setLroRetrySettings(lroRetrySettingsOpt);
@@ -123,9 +128,7 @@ public static GapicContext parse(CodeGeneratorRequest request) {
     Optional<String> serviceYamlConfigPathOpt =
         PluginArgumentParser.parseServiceYamlConfigPath(request);
     Optional<com.google.api.Service> serviceYamlProtoOpt =
-        serviceYamlConfigPathOpt.isPresent()
-            ? ServiceYamlParser.parse(serviceYamlConfigPathOpt.get())
-            : Optional.empty();
+        serviceYamlConfigPathOpt.flatMap(ServiceYamlParser::parse);
 
     // Collect the resource references seen in messages.
     Set<ResourceReference> outputResourceReferencesSeen = new HashSet<>();
@@ -137,8 +140,15 @@ public static GapicContext parse(CodeGeneratorRequest request) {
     Map<String, ResourceName> resourceNames = parseResourceNames(request);
     messages = updateResourceNamesInMessages(messages, resourceNames.values());
 
+    // Contains only resource names that are actually used. Usage refers to the presence of a
+    // request message's field in an RPC's method_signature annotation. That is,  resource name
+    // definitions
+    // or references that are simply defined, but not used in such a manner, will not have
+    // corresponding Java helper
+    // classes generated.
     Set<ResourceName> outputArgResourceNames = new HashSet<>();
     List<Service> mixinServices = new ArrayList<>();
+    Transport transport = Transport.parse(transportOpt.orElse(Transport.GRPC.toString()));
     List<Service> services =
         parseServices(
             request,
@@ -147,34 +157,41 @@ public static GapicContext parse(CodeGeneratorRequest request) {
             outputArgResourceNames,
             serviceYamlProtoOpt,
             serviceConfigOpt,
-            mixinServices);
+            mixinServices,
+            transport);
 
     Preconditions.checkState(!services.isEmpty(), "No services found to generate");
-    Function<ResourceName, String> typeNameFn =
-        r -> r.resourceTypeString().substring(r.resourceTypeString().indexOf("/") + 1);
-    Function<Set<ResourceName>, Set<String>> typeStringSetFn =
-        sr -> sr.stream().map(r -> typeNameFn.apply(r)).collect(Collectors.toSet());
-
-    // Include all resource names present in message types for backwards-compatibility with the
-    // monolith. In the future, this should be removed on a client library major semver update.
-    // Resolve type name collisions with the ones present in the method arguments.
-    final Set<String> typeStringSet = typeStringSetFn.apply(outputArgResourceNames);
-    outputArgResourceNames.addAll(
-        resourceNames.values().stream()
-            .filter(r -> r.hasParentMessageName() && !typeStringSet.contains(typeNameFn.apply(r)))
-            .collect(Collectors.toSet()));
-
-    String servicePackage = services.get(0).pakkage();
-    Map<String, ResourceName> patternsToResourceNames =
-        ResourceParserHelpers.createPatternResourceNameMap(resourceNames);
-    for (ResourceReference resourceReference : outputResourceReferencesSeen) {
-      final Set<String> interimTypeStringSet = typeStringSetFn.apply(outputArgResourceNames);
+
+    // TODO(vam-google): Figure out whether we should keep this allowlist or bring
+    // back the unused resource names for all APIs.
+    // Temporary workaround for Ads, who still need these resource names.
+    if (services.get(0).protoPakkage().startsWith("google.ads.googleads.v")) {
+      Function<ResourceName, String> typeNameFn =
+          r -> r.resourceTypeString().substring(r.resourceTypeString().indexOf("/") + 1);
+      Function<Set<ResourceName>, Set<String>> typeStringSetFn =
+          sr -> sr.stream().map(typeNameFn).collect(Collectors.toSet());
+
+      // Include all resource names present in message types for backwards-compatibility with the
+      // monolith. In the future, this should be removed on a client library major semver update.
+      // Resolve type name collisions with the ones present in the method arguments.
+      final Set<String> typeStringSet = typeStringSetFn.apply(outputArgResourceNames);
       outputArgResourceNames.addAll(
-          ResourceReferenceParser.parseResourceNames(
-                  resourceReference, servicePackage, null, resourceNames, patternsToResourceNames)
-              .stream()
-              .filter(r -> !interimTypeStringSet.contains(typeNameFn.apply(r)))
+          resourceNames.values().stream()
+              .filter(r -> r.hasParentMessageName() && !typeStringSet.contains(typeNameFn.apply(r)))
               .collect(Collectors.toSet()));
+
+      String servicePackage = services.get(0).pakkage();
+      Map<String, ResourceName> patternsToResourceNames =
+          ResourceParserHelpers.createPatternResourceNameMap(resourceNames);
+      for (ResourceReference resourceReference : outputResourceReferencesSeen) {
+        final Set<String> interimTypeStringSet = typeStringSetFn.apply(outputArgResourceNames);
+        outputArgResourceNames.addAll(
+            ResourceReferenceParser.parseResourceNames(
+                    resourceReference, servicePackage, null, resourceNames, patternsToResourceNames)
+                .stream()
+                .filter(r -> !interimTypeStringSet.contains(typeNameFn.apply(r)))
+                .collect(Collectors.toSet()));
+      }
     }
 
     return GapicContext.builder()
@@ -183,10 +200,10 @@ public static GapicContext parse(CodeGeneratorRequest request) {
         .setMessages(messages)
         .setResourceNames(resourceNames)
         .setHelperResourceNames(outputArgResourceNames)
-        .setServiceConfig(serviceConfigOpt.isPresent() ? serviceConfigOpt.get() : null)
+        .setServiceConfig(serviceConfigOpt.orElse(null))
         .setGapicMetadataEnabled(willGenerateMetadata)
-        .setServiceYamlProto(serviceYamlProtoOpt.isPresent() ? serviceYamlProtoOpt.get() : null)
-        .setTransport(Transport.GRPC)
+        .setServiceYamlProto(serviceYamlProtoOpt.orElse(null))
+        .setTransport(transport)
         .build();
   }
 
@@ -197,7 +214,8 @@ public static List<Service> parseServices(
       Set<ResourceName> outputArgResourceNames,
       Optional<com.google.api.Service> serviceYamlProtoOpt,
       Optional<GapicServiceConfig> serviceConfigOpt,
-      List<Service> outputMixinServices) {
+      List<Service> outputMixinServices,
+      Transport transport) {
     Map<String, FileDescriptor> fileDescriptors = getFilesToGenerate(request);
 
     List<Service> services = new ArrayList<>();
@@ -215,7 +233,8 @@ public static List<Service> parseServices(
               resourceNames,
               serviceYamlProtoOpt,
               serviceConfigOpt,
-              outputArgResourceNames));
+              outputArgResourceNames,
+              transport));
     }
 
     // Prevent codegen for mixed-in services if there are other services present, since that is an
@@ -247,18 +266,18 @@ public static List<Service> parseServices(
     // Key: proto_package.ServiceName.RpcName.
     // Value: HTTP rules, which clobber those in the proto.
     // Assumes that http.rules.selector always specifies RPC names in the above format.
-    Map<String, List<String>> mixedInMethodsToHttpRules = new HashMap<>();
+    Map<String, HttpBindings> mixedInMethodsToHttpRules = new HashMap<>();
     Map<String, String> mixedInMethodsToDocs = new HashMap<>();
     // Parse HTTP rules and documentation, which will override the proto.
     if (serviceYamlProtoOpt.isPresent()) {
       for (HttpRule httpRule : serviceYamlProtoOpt.get().getHttp().getRulesList()) {
-        Optional<List<String>> httpBindingsOpt = HttpRuleParser.parseHttpRule(httpRule);
-        if (!httpBindingsOpt.isPresent()) {
+        HttpBindings httpBindings = HttpRuleParser.parseHttpRule(httpRule);
+        if (httpBindings == null) {
           continue;
         }
         for (String rpcFullNameRaw : httpRule.getSelector().split(",")) {
           String rpcFullName = rpcFullNameRaw.trim();
-          mixedInMethodsToHttpRules.put(rpcFullName, httpBindingsOpt.get());
+          mixedInMethodsToHttpRules.put(rpcFullName, httpBindings);
         }
       }
       for (DocumentationRule docRule :
@@ -270,9 +289,15 @@ public static List<Service> parseServices(
       }
     }
 
+    // Sort potential mixin services alphabetically.
+    List<Service> orderedBlockedCodegenMixinApis =
+        blockedCodegenMixinApis.stream()
+            .sorted((s1, s2) -> s2.name().compareTo(s1.name()))
+            .collect(Collectors.toList());
+
     Set<String> apiDefinedRpcs = new HashSet<>();
     for (Service service : services) {
-      if (blockedCodegenMixinApis.contains(service)) {
+      if (orderedBlockedCodegenMixinApis.contains(service)) {
         continue;
       }
       apiDefinedRpcs.addAll(
@@ -285,7 +310,7 @@ public static List<Service> parseServices(
         Service originalService = services.get(i);
         List<Method> updatedOriginalServiceMethods = new ArrayList<>(originalService.methods());
         // If mixin APIs are present, add the methods to all other services.
-        for (Service mixinService : blockedCodegenMixinApis) {
+        for (Service mixinService : orderedBlockedCodegenMixinApis) {
           final String mixinServiceFullName = serviceFullNameFn.apply(mixinService);
           if (!mixedInApis.contains(mixinServiceFullName)) {
             continue;
@@ -304,7 +329,7 @@ public static List<Service> parseServices(
                         // HTTP rules and RPC documentation in the service.yaml file take
                         // precedence.
                         String fullMethodName = methodToFullProtoNameFn.apply(m);
-                        List<String> httpBindings =
+                        HttpBindings httpBindings =
                             mixedInMethodsToHttpRules.containsKey(fullMethodName)
                                 ? mixedInMethodsToHttpRules.get(fullMethodName)
                                 : m.httpBindings();
@@ -327,6 +352,11 @@ public static List<Service> parseServices(
                           m.toBuilder()
                               .setMixedInApiName(serviceFullNameFn.apply(mixinService))
                               .build()));
+          // Sort by method name, to ensure a deterministic method ordering (for tests).
+          updatedMixinMethods =
+              updatedMixinMethods.stream()
+                  .sorted((m1, m2) -> m2.name().compareTo(m1.name()))
+                  .collect(Collectors.toList());
           outputMixinServiceSet.add(
               mixinService.toBuilder().setMethods(updatedMixinMethods).build());
         }
@@ -343,7 +373,10 @@ public static List<Service> parseServices(
     }
 
     // Use a list to ensure ordering for deterministic tests.
-    outputMixinServices.addAll(outputMixinServiceSet);
+    outputMixinServices.addAll(
+        outputMixinServiceSet.stream()
+            .sorted((s1, s2) -> s2.name().compareTo(s1.name()))
+            .collect(Collectors.toList()));
     return services;
   }
 
@@ -360,7 +393,8 @@ public static List<Service> parseService(
         resourceNames,
         serviceYamlProtoOpt,
         Optional.empty(),
-        outputArgResourceNames);
+        outputArgResourceNames,
+        Transport.GRPC);
   }
 
   public static List<Service> parseService(
@@ -369,7 +403,8 @@ public static List<Service> parseService(
       Map<String, ResourceName> resourceNames,
       Optional<com.google.api.Service> serviceYamlProtoOpt,
       Optional<GapicServiceConfig> serviceConfigOpt,
-      Set<ResourceName> outputArgResourceNames) {
+      Set<ResourceName> outputArgResourceNames,
+      Transport transport) {
 
     return fileDescriptor.getServices().stream()
         .map(
@@ -443,7 +478,8 @@ public static List<Service> parseService(
                           messageTypes,
                           resourceNames,
                           serviceConfigOpt,
-                          outputArgResourceNames))
+                          outputArgResourceNames,
+                          transport))
                   .build();
             })
         .collect(Collectors.toList());
@@ -495,7 +531,7 @@ public static Map<String, Message> parseMessages(
 
   private static Map<String, Message> parseMessages(
       Descriptor messageDescriptor, Set<ResourceReference> outputResourceReferencesSeen) {
-    return parseMessages(messageDescriptor, outputResourceReferencesSeen, new ArrayList<String>());
+    return parseMessages(messageDescriptor, outputResourceReferencesSeen, new ArrayList<>());
   }
 
   private static Map<String, Message> parseMessages(
@@ -542,7 +578,7 @@ private static boolean isMapType(Descriptor messageDescriptor) {
    * Populates ResourceName objects in Message POJOs.
    *
    * @param messageTypes A map of the message type name (as in the protobuf) to Message POJOs.
-   * @param resourceNames A list of ResourceName POJOs.
+   * @param resources A list of ResourceName POJOs.
    * @return The updated messageTypes map.
    */
   public static Map<String, Message> updateResourceNamesInMessages(
@@ -560,7 +596,7 @@ public static Map<String, Message> updateResourceNamesInMessages(
   }
 
   public static Map<String, ResourceName> parseResourceNames(CodeGeneratorRequest request) {
-    @VisibleForTesting String javaPackage = parseServiceJavaPackage(request);
+    String javaPackage = parseServiceJavaPackage(request);
     Map<String, FileDescriptor> fileDescriptors = getFilesToGenerate(request);
     Map<String, ResourceName> resourceNames = new HashMap<>();
     for (String fileToGenerate : request.getFileToGenerateList()) {
@@ -591,7 +627,8 @@ static List<Method> parseMethods(
       Map<String, Message> messageTypes,
       Map<String, ResourceName> resourceNames,
       Optional<GapicServiceConfig> serviceConfigOpt,
-      Set<ResourceName> outputArgResourceNames) {
+      Set<ResourceName> outputArgResourceNames,
+      Transport transport) {
     List<Method> methods = new ArrayList<>();
     for (MethodDescriptor protoMethod : serviceDescriptor.getMethods()) {
       // Parse the method.
@@ -614,10 +651,7 @@ static List<Method> parseMethods(
       Message inputMessage = messageTypes.get(inputType.reference().fullName());
       Preconditions.checkNotNull(
           inputMessage, String.format("No message found for %s", inputType.reference().fullName()));
-      Optional<List<String>> httpBindingsOpt =
-          HttpRuleParser.parseHttpBindings(protoMethod, inputMessage, messageTypes);
-      List<String> httpBindings =
-          httpBindingsOpt.isPresent() ? httpBindingsOpt.get() : Collections.emptyList();
+      HttpBindings httpBindings = HttpRuleParser.parse(protoMethod, inputMessage, messageTypes);
       boolean isBatching =
           !serviceConfigOpt.isPresent()
               ? false
@@ -646,7 +680,7 @@ static List<Method> parseMethods(
                       outputArgResourceNames))
               .setHttpBindings(httpBindings)
               .setIsBatching(isBatching)
-              .setIsPaged(parseIsPaged(protoMethod, messageTypes))
+              .setPageSizeFieldName(parsePageSizeFieldName(protoMethod, messageTypes, transport))
               .setIsDeprecated(isDeprecated)
               .build());
 
@@ -761,8 +795,8 @@ static LongrunningOperation parseLro(
   }
 
   @VisibleForTesting
-  static boolean parseIsPaged(
-      MethodDescriptor methodDescriptor, Map<String, Message> messageTypes) {
+  static String parsePageSizeFieldName(
+      MethodDescriptor methodDescriptor, Map<String, Message> messageTypes, Transport transport) {
     TypeNode inputMessageType = TypeParser.parseType(methodDescriptor.getInputType());
     TypeNode outputMessageType = TypeParser.parseType(methodDescriptor.getOutputType());
     Message inputMessage = messageTypes.get(inputMessageType.reference().fullName());
@@ -771,14 +805,29 @@ static boolean parseIsPaged(
     // This should technically handle the absence of either of these fields (aip.dev/158), but we
     // gate on their collective presence to ensure the generated surface is backawrds-compatible
     // with monolith-gnerated libraries.
-    return inputMessage.fieldMap().containsKey("page_size")
-        && inputMessage.fieldMap().containsKey("page_token")
-        && outputMessage.fieldMap().containsKey("next_page_token");
+    String pagedFieldName = null;
+
+    if (inputMessage.fieldMap().containsKey("page_token")
+        && outputMessage.fieldMap().containsKey("next_page_token")) {
+      // List of potential field names representing page size.
+      // page_size gets priority over max_results if both are present
+      List<String> fieldNames = new ArrayList<>();
+      fieldNames.add("page_size");
+      if (transport == Transport.REST) {
+        fieldNames.add("max_results");
+      }
+      for (String fieldName : fieldNames) {
+        if (pagedFieldName == null && inputMessage.fieldMap().containsKey(fieldName)) {
+          pagedFieldName = fieldName;
+        }
+      }
+    }
+    return pagedFieldName;
   }
 
   @VisibleForTesting
   static String sanitizeDefaultHost(String rawDefaultHost) {
-    if (rawDefaultHost.indexOf(COLON) >= 0) {
+    if (rawDefaultHost.contains(COLON)) {
       // A port is already present, just return the existing string.
       return rawDefaultHost;
     }
@@ -791,14 +840,47 @@ private static List<Field> parseFields(
     // Sort by ascending field index order. This is important for paged responses, where the first
     // repeated type is taken.
     fields.sort((f1, f2) -> f1.getIndex() - f2.getIndex());
+
+    // Mirror protoc's name conflict resolution behavior for fields.
+    // If a singular field's name equals that of a repeated field with "Count" or "List" suffixed,
+    // append the protobuf's field number to both fields' names.
+    // See:
+    // https://github.com/protocolbuffers/protobuf/blob/9df42757f97da9f748a464deeda96427a8f7ade0/src/google/protobuf/compiler/java/java_context.cc#L60
+    Map<String, Integer> repeatedFieldNamesToNumber =
+        fields.stream()
+            .filter(f -> f.isRepeated())
+            .collect(Collectors.toMap(f -> f.getName(), f -> f.getNumber()));
+    Set<Integer> fieldNumbersWithConflicts = new HashSet<>();
+    for (FieldDescriptor field : fields) {
+      Set<String> conflictingRepeatedFieldNames =
+          repeatedFieldNamesToNumber.keySet().stream()
+              .filter(
+                  n -> field.getName().equals(n + "_count") || field.getName().equals(n + "_list"))
+              .collect(Collectors.toSet());
+      if (!conflictingRepeatedFieldNames.isEmpty()) {
+        fieldNumbersWithConflicts.addAll(
+            conflictingRepeatedFieldNames.stream()
+                .map(n -> repeatedFieldNamesToNumber.get(n))
+                .collect(Collectors.toSet()));
+        fieldNumbersWithConflicts.add(field.getNumber());
+      }
+    }
+
     return fields.stream()
-        .map(f -> parseField(f, messageDescriptor, outputResourceReferencesSeen))
+        .map(
+            f ->
+                parseField(
+                    f,
+                    messageDescriptor,
+                    fieldNumbersWithConflicts.contains(f.getNumber()),
+                    outputResourceReferencesSeen))
         .collect(Collectors.toList());
   }
 
   private static Field parseField(
       FieldDescriptor fieldDescriptor,
       Descriptor messageDescriptor,
+      boolean hasFieldNameConflict,
       Set<ResourceReference> outputResourceReferencesSeen) {
     FieldOptions fieldOptions = fieldDescriptor.getOptions();
     MessageOptions messageOptions = messageDescriptor.getOptions();
@@ -843,12 +925,25 @@ private static Field parseField(
       }
     }
 
+    // Mirror protoc's name conflict resolution behavior for fields.
+    // For more context, trace hasFieldNameConflict back to where it gets passed in above.
+    String actualFieldName =
+        hasFieldNameConflict
+            ? fieldDescriptor.getName() + fieldDescriptor.getNumber()
+            : fieldDescriptor.getName();
+
     return fieldBuilder
-        .setName(fieldDescriptor.getName())
+        .setName(actualFieldName)
+        .setOriginalName(fieldDescriptor.getName())
         .setType(TypeParser.parseType(fieldDescriptor))
         .setIsMessage(fieldDescriptor.getJavaType() == FieldDescriptor.JavaType.MESSAGE)
         .setIsEnum(fieldDescriptor.getJavaType() == FieldDescriptor.JavaType.ENUM)
-        .setIsContainedInOneof(fieldDescriptor.getContainingOneof() != null)
+        .setIsContainedInOneof(
+            fieldDescriptor.getContainingOneof() != null
+                && !fieldDescriptor.getContainingOneof().isSynthetic())
+        .setIsProto3Optional(
+            fieldDescriptor.getContainingOneof() != null
+                && fieldDescriptor.getContainingOneof().isSynthetic())
         .setIsRepeated(fieldDescriptor.isRepeated())
         .setIsMap(fieldDescriptor.isMapField())
         .setResourceReference(resourceReference)
@@ -903,8 +998,23 @@ private static String parseServiceJavaPackage(CodeGeneratorRequest request) {
       }
     }
 
+    // Filter out mixin packages.
+    Map<String, Integer> processedJavaPackageCount =
+        javaPackageCount.entrySet().stream()
+            .filter(e -> !MIXIN_JAVA_PACKAGE_ALLOWLIST.contains(e.getKey()))
+            .collect(Collectors.toMap(e -> e.getKey(), e -> e.getValue()));
+
+    // An empty map indicates that only mixin packages were present, which means that we're
+    // generating a standalone client for a mixin.
+    if (processedJavaPackageCount.isEmpty()) {
+      processedJavaPackageCount = javaPackageCount;
+    }
+
     String finalJavaPackage =
-        javaPackageCount.entrySet().stream().max(Map.Entry.comparingByValue()).get().getKey();
+        processedJavaPackageCount.entrySet().stream()
+            .max(Map.Entry.comparingByValue())
+            .get()
+            .getKey();
     Preconditions.checkState(
         !Strings.isNullOrEmpty(finalJavaPackage), "No service Java package found");
     return finalJavaPackage;
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/PluginArgumentParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/PluginArgumentParser.java
index 53cd0f32f3..d5a7de1f79 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/PluginArgumentParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/PluginArgumentParser.java
@@ -30,6 +30,7 @@ public class PluginArgumentParser {
   @VisibleForTesting static final String KEY_GAPIC_CONFIG = "gapic-config";
   @VisibleForTesting static final String KEY_METADATA = "metadata";
   @VisibleForTesting static final String KEY_SERVICE_YAML_CONFIG = "api-service-config";
+  @VisibleForTesting static final String KEY_TRANSPORT = "transport";
 
   private static final String JSON_FILE_ENDING = "grpc_service_config.json";
   private static final String GAPIC_YAML_FILE_ENDING = "gapic.yaml";
@@ -47,6 +48,10 @@ static Optional<String> parseServiceYamlConfigPath(CodeGeneratorRequest request)
     return parseServiceYamlConfigPath(request.getParameter());
   }
 
+  static Optional<String> parseTransport(CodeGeneratorRequest request) {
+    return parseConfigArgument(request.getParameter(), KEY_TRANSPORT);
+  }
+
   static boolean hasMetadataFlag(CodeGeneratorRequest request) {
     return hasMetadataFlag(request.getParameter());
   }
@@ -54,17 +59,33 @@ static boolean hasMetadataFlag(CodeGeneratorRequest request) {
   /** Expects a comma-separated list of file paths. */
   @VisibleForTesting
   static Optional<String> parseJsonConfigPath(String pluginProtocArgument) {
-    return parseArgument(pluginProtocArgument, KEY_GRPC_SERVICE_CONFIG, JSON_FILE_ENDING);
+    return parseFileArgument(pluginProtocArgument, KEY_GRPC_SERVICE_CONFIG, JSON_FILE_ENDING);
   }
 
   @VisibleForTesting
   static Optional<String> parseGapicYamlConfigPath(String pluginProtocArgument) {
-    return parseArgument(pluginProtocArgument, KEY_GAPIC_CONFIG, GAPIC_YAML_FILE_ENDING);
+    return parseFileArgument(pluginProtocArgument, KEY_GAPIC_CONFIG, GAPIC_YAML_FILE_ENDING);
   }
 
   @VisibleForTesting
   static Optional<String> parseServiceYamlConfigPath(String pluginProtocArgument) {
-    return parseArgument(pluginProtocArgument, KEY_SERVICE_YAML_CONFIG, SERVICE_YAML_FILE_ENDING);
+    return parseFileArgument(
+        pluginProtocArgument, KEY_SERVICE_YAML_CONFIG, SERVICE_YAML_FILE_ENDING);
+  }
+
+  @VisibleForTesting
+  private static Optional<String> parseConfigArgument(String pluginProtocArgument, String key) {
+    if (Strings.isNullOrEmpty(pluginProtocArgument)) {
+      return Optional.empty();
+    }
+
+    for (String argComponent : pluginProtocArgument.split(COMMA)) {
+      String[] args = argComponent.trim().split(EQUALS);
+      if (args.length == 2 && key.equals(args[0])) {
+        return Optional.of(args[1]);
+      }
+    }
+    return Optional.empty();
   }
 
   @VisibleForTesting
@@ -72,10 +93,10 @@ static boolean hasMetadataFlag(String pluginProtocArgument) {
     return Arrays.stream(pluginProtocArgument.split(COMMA)).anyMatch(s -> s.equals(KEY_METADATA));
   }
 
-  private static Optional<String> parseArgument(
+  private static Optional<String> parseFileArgument(
       String pluginProtocArgument, String key, String fileEnding) {
     if (Strings.isNullOrEmpty(pluginProtocArgument)) {
-      return Optional.<String>empty();
+      return Optional.empty();
     }
     for (String argComponent : pluginProtocArgument.split(COMMA)) {
       String[] args = argComponent.trim().split(EQUALS);
@@ -93,6 +114,6 @@ private static Optional<String> parseArgument(
         return Optional.of(valueVal);
       }
     }
-    return Optional.<String>empty();
+    return Optional.empty();
   }
 }
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/ServiceYamlParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/ServiceYamlParser.java
index 839903d460..5b136b897f 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/ServiceYamlParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/ServiceYamlParser.java
@@ -21,6 +21,7 @@
 import com.google.protobuf.util.JsonFormat;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.LinkedHashMap;
@@ -37,7 +38,8 @@ public static Optional<com.google.api.Service> parse(String serviceYamlFilePath)
 
     String fileContents = null;
     try {
-      fileContents = new String(Files.readAllBytes(Paths.get(serviceYamlFilePath)));
+      fileContents =
+          new String(Files.readAllBytes(Paths.get(serviceYamlFilePath)), StandardCharsets.UTF_8);
     } catch (IOException e) {
       return Optional.empty();
     }
diff --git a/src/main/java/com/google/api/generator/gapic/protoparser/TypeParser.java b/src/main/java/com/google/api/generator/gapic/protoparser/TypeParser.java
index 7a4542ee25..49b17d25db 100644
--- a/src/main/java/com/google/api/generator/gapic/protoparser/TypeParser.java
+++ b/src/main/java/com/google/api/generator/gapic/protoparser/TypeParser.java
@@ -37,8 +37,6 @@
 import javax.annotation.Nonnull;
 
 public class TypeParser {
-  private static final String DOT = ".";
-
   private static Reference REFERENCE_BYTE_STRING = ConcreteReference.withClazz(ByteString.class);
   private static TypeNode TYPE_NODE_BYTE_STRING = TypeNode.withReference(REFERENCE_BYTE_STRING);
 
@@ -245,8 +243,6 @@ static Reference parseEnumReference(@Nonnull EnumDescriptor enumDescriptor) {
 
   @VisibleForTesting
   static TypeNode createListType(FieldDescriptor field) {
-    JavaType protoFieldType = field.getJavaType();
-
     Reference listReference =
         ConcreteReference.builder()
             .setClazz(List.class)
@@ -259,7 +255,6 @@ static TypeNode createListType(FieldDescriptor field) {
   static TypeNode createMapType(FieldDescriptor field) {
     Preconditions.checkState(
         field.isMapField(), "createMapType can only be called on map-type fields");
-    JavaType protoJavaType = field.getJavaType();
 
     Descriptor type = field.getMessageType();
     FieldDescriptor keyField = type.findFieldByName("key");
diff --git a/src/main/java/com/google/api/generator/gapic/protowriter/Writer.java b/src/main/java/com/google/api/generator/gapic/protowriter/Writer.java
index 0113776cee..634174acca 100644
--- a/src/main/java/com/google/api/generator/gapic/protowriter/Writer.java
+++ b/src/main/java/com/google/api/generator/gapic/protowriter/Writer.java
@@ -24,6 +24,7 @@
 import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse;
 import com.google.protobuf.util.JsonFormat;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.jar.JarEntry;
 import java.util.jar.JarOutputStream;
@@ -61,7 +62,7 @@ public static CodeGeneratorResponse write(
       JarEntry jarEntry = new JarEntry(String.format("%s/%s.java", path, className));
       try {
         jos.putNextEntry(jarEntry);
-        jos.write(code.getBytes());
+        jos.write(code.getBytes(StandardCharsets.UTF_8));
       } catch (IOException e) {
         throw new GapicWriterException(
             String.format(
@@ -80,7 +81,7 @@ public static CodeGeneratorResponse write(
     JarEntry jarEntry = new JarEntry(String.format("%s/package-info.java", path));
     try {
       jos.putNextEntry(jarEntry);
-      jos.write(code.getBytes());
+      jos.write(code.getBytes(StandardCharsets.UTF_8));
     } catch (IOException e) {
       throw new GapicWriterException("Could not write code for package-info.java");
     }
@@ -90,7 +91,8 @@ public static CodeGeneratorResponse write(
       jarEntry = new JarEntry(String.format("%s/gapic_metadata.json", path));
       try {
         jos.putNextEntry(jarEntry);
-        jos.write(JsonFormat.printer().print(context.gapicMetadata()).getBytes());
+        jos.write(
+            JsonFormat.printer().print(context.gapicMetadata()).getBytes(StandardCharsets.UTF_8));
       } catch (IOException e) {
         throw new GapicWriterException("Could not write gapic_metadata.json");
       }
diff --git a/src/main/java/com/google/api/generator/util/Trie.java b/src/main/java/com/google/api/generator/util/Trie.java
index 51a26180bc..4134b3f543 100644
--- a/src/main/java/com/google/api/generator/util/Trie.java
+++ b/src/main/java/com/google/api/generator/util/Trie.java
@@ -24,17 +24,17 @@
  * A common-prefix trie. T represents the type of each "char" in a word (which is a T-typed list).
  */
 public class Trie<T> {
-  private class Node<T> {
-    final T chr;
+  private class Node<U> {
+    final U chr;
     // Maintain insertion order to enable deterministic test output.
-    Map<T, Node<T>> children = new LinkedHashMap<>();
+    Map<U, Node<U>> children = new LinkedHashMap<>();
     boolean isLeaf;
 
     Node() {
       chr = null;
     }
 
-    Node(T chr) {
+    Node(U chr) {
       this.chr = chr;
     }
   }
@@ -42,18 +42,18 @@ private class Node<T> {
   private Node<T> root;
 
   public Trie() {
-    root = new Node();
+    root = new Node<>();
   }
 
   public void insert(List<T> word) {
     Map<T, Node<T>> children = root.children;
     for (int i = 0; i < word.size(); i++) {
       T chr = word.get(i);
-      Node t;
+      Node<T> t;
       if (children.containsKey(chr)) {
         t = children.get(chr);
       } else {
-        t = new Node(chr);
+        t = new Node<>(chr);
         children.put(chr, t);
       }
       children = t.children;
@@ -65,7 +65,7 @@ public void insert(List<T> word) {
 
   /** Returns true if the word is in the trie. */
   public boolean search(List<T> word) {
-    Node node = searchNode(word);
+    Node<T> node = searchNode(word);
     return node != null && node.isLeaf;
   }
 
@@ -119,11 +119,10 @@ private <R> R dfsTraverseAndReduce(
     return parentPostprocFn.apply(node.chr, baseValue, leafReducedValue);
   }
 
-  private Node searchNode(List<T> word) {
+  private Node<T> searchNode(List<T> word) {
     Map<T, Node<T>> children = root.children;
-    Node t = null;
-    for (int i = 0; i < word.size(); i++) {
-      T chr = word.get(i);
+    Node<T> t = null;
+    for (T chr : word) {
       if (children.containsKey(chr)) {
         t = children.get(chr);
         children = t.children;
diff --git a/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java b/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java
index 8ed58c13cb..607ccd89f6 100644
--- a/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java
+++ b/src/test/java/com/google/api/generator/engine/JavaCodeGeneratorTest.java
@@ -297,7 +297,7 @@ private VariableExpr createVarPublicDeclExpr(Variable var) {
         .build();
   }
 
-  private NewObjectExpr createNewObjectExpr(Class clazz) {
+  private NewObjectExpr createNewObjectExpr(Class<?> clazz) {
     return NewObjectExpr.builder()
         .setType(TypeNode.withReference(ConcreteReference.withClazz(clazz)))
         .setIsGeneric(true)
@@ -460,11 +460,8 @@ private MethodDefinition createOverrideCreateBookMethod(
   }
 
   private MethodDefinition createAddShelfMethod() {
-    ConcreteReference integerUtilRef =
-        ConcreteReference.builder().setClazz(Integer.class).setIsStaticImport(true).build();
     Variable nameVar = createVarFromType(TypeNode.STRING, "name");
     Variable seriesDoubleNumVar = createVarFromType(TypeNode.DOUBLE, "seriesDoubleNum");
-    Variable maxValueVar = createVarFromConcreteRef(integerUtilRef, "MAX_VALUE");
     CastExpr seriesNumDoubleToIntExpr =
         CastExpr.builder()
             .setExpr(VariableExpr.withVariable(seriesDoubleNumVar))
@@ -606,8 +603,8 @@ private MethodDefinition createPrintShelfListToFile() {
                     loopShelfList,
                     ExprStatement.withExpr(writeToFileWriter),
                     ExprStatement.withExpr(closeFileWriter)))
-            .setCatchVariableExpr(createVarDeclExpr(ioException))
-            .setCatchBody(Arrays.asList(ExprStatement.withExpr(printError)))
+            .addCatch(
+                createVarDeclExpr(ioException), Arrays.asList(ExprStatement.withExpr(printError)))
             .build();
 
     return MethodDefinition.builder()
diff --git a/src/test/java/com/google/api/generator/engine/ast/AnonymousClassExprTest.java b/src/test/java/com/google/api/generator/engine/ast/AnonymousClassExprTest.java
index b53fa9e77b..9fab46d98d 100644
--- a/src/test/java/com/google/api/generator/engine/ast/AnonymousClassExprTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/AnonymousClassExprTest.java
@@ -14,9 +14,9 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 
 import com.google.common.base.Function;
 import java.util.Arrays;
@@ -103,10 +103,7 @@ public void validAnonymousClass_genericAndVariableExpr() {
   public void invalidAnonymousClass_primitiveType() {
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          AnonymousClassExpr anonymousClassExpr =
-              AnonymousClassExpr.builder().setType(TypeNode.INT).build();
-        });
+        () -> AnonymousClassExpr.builder().setType(TypeNode.INT).build());
   }
 
   @Test
@@ -126,10 +123,7 @@ public void invalidAnonymousClass_staticMethod() {
 
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          AnonymousClassExpr anonymousClassExpr =
-              AnonymousClassExpr.builder().setType(type).setMethods(Arrays.asList(method)).build();
-        });
+        () -> AnonymousClassExpr.builder().setType(type).setMethods(Arrays.asList(method)).build());
   }
 
   @Test
@@ -145,10 +139,7 @@ public void invalidAnonymousClass_explicitConstructor() {
             .build();
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          AnonymousClassExpr anonymousClassExpr =
-              AnonymousClassExpr.builder().setType(type).setMethods(Arrays.asList(method)).build();
-        });
+        () -> AnonymousClassExpr.builder().setType(type).setMethods(Arrays.asList(method)).build());
   }
 
   @Test
@@ -162,13 +153,11 @@ public void invalidAnonymousClass_staticVariableExpr() {
     ExprStatement exprStatement = ExprStatement.withExpr(variableExpr);
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          AnonymousClassExpr anonymousClassExpr =
-              AnonymousClassExpr.builder()
-                  .setType(type)
-                  .setStatements(Arrays.asList(exprStatement))
-                  .build();
-        });
+        () ->
+            AnonymousClassExpr.builder()
+                .setType(type)
+                .setStatements(Arrays.asList(exprStatement))
+                .build());
   }
 
   private static AssignmentExpr createAssignmentExpr(
diff --git a/src/test/java/com/google/api/generator/engine/ast/CastExprTest.java b/src/test/java/com/google/api/generator/engine/ast/CastExprTest.java
index f39bff072a..04bb8a05ca 100644
--- a/src/test/java/com/google/api/generator/engine/ast/CastExprTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/CastExprTest.java
@@ -32,8 +32,6 @@ public void validCastExpr_basic() {
 
   @Test
   public void validCastExpr_basicNull() {
-    Variable variable = Variable.builder().setName("x").setType(TypeNode.STRING).build();
-    VariableExpr variableExpr = VariableExpr.builder().setVariable(variable).build();
     CastExpr.builder()
         .setType(TypeNode.withReference(ConcreteReference.withClazz(Object.class)))
         .setExpr(ValueExpr.createNullExpr())
diff --git a/src/test/java/com/google/api/generator/engine/ast/ConcreteReferenceTest.java b/src/test/java/com/google/api/generator/engine/ast/ConcreteReferenceTest.java
index d45c9bdc37..6fdc65a937 100644
--- a/src/test/java/com/google/api/generator/engine/ast/ConcreteReferenceTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/ConcreteReferenceTest.java
@@ -14,9 +14,9 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import java.util.ArrayList;
 import java.util.Arrays;
diff --git a/src/test/java/com/google/api/generator/engine/ast/ForStatementTest.java b/src/test/java/com/google/api/generator/engine/ast/ForStatementTest.java
index 7eb401637f..569eebb3c0 100644
--- a/src/test/java/com/google/api/generator/engine/ast/ForStatementTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/ForStatementTest.java
@@ -49,14 +49,12 @@ public void invalidForStatement() {
         MethodInvocationExpr.builder().setMethodName("getSomeStrings").build();
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          ForStatement forStatement =
-              ForStatement.builder()
-                  .setLocalVariableExpr(variableExpr)
-                  .setCollectionExpr(methodExpr)
-                  .setBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
-                  .build();
-        });
+        () ->
+            ForStatement.builder()
+                .setLocalVariableExpr(variableExpr)
+                .setCollectionExpr(methodExpr)
+                .setBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
+                .build());
   }
 
   private static AssignmentExpr createAssignmentExpr() {
diff --git a/src/test/java/com/google/api/generator/engine/ast/IdentifierNodeTest.java b/src/test/java/com/google/api/generator/engine/ast/IdentifierNodeTest.java
index b4a7453337..ead7d8be37 100644
--- a/src/test/java/com/google/api/generator/engine/ast/IdentifierNodeTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/IdentifierNodeTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import com.google.api.generator.engine.ast.IdentifierNode.InvalidIdentifierException;
diff --git a/src/test/java/com/google/api/generator/engine/ast/JavaDocCommentTest.java b/src/test/java/com/google/api/generator/engine/ast/JavaDocCommentTest.java
index 8e969a4f45..0d3550971d 100644
--- a/src/test/java/com/google/api/generator/engine/ast/JavaDocCommentTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/JavaDocCommentTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.testutils.LineFormatter;
 import java.util.Arrays;
diff --git a/src/test/java/com/google/api/generator/engine/ast/NewObjectExprTest.java b/src/test/java/com/google/api/generator/engine/ast/NewObjectExprTest.java
index 1bc2c48cd6..2287a75394 100644
--- a/src/test/java/com/google/api/generator/engine/ast/NewObjectExprTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/NewObjectExprTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import java.util.Arrays;
diff --git a/src/test/java/com/google/api/generator/engine/ast/NullObjectValueTest.java b/src/test/java/com/google/api/generator/engine/ast/NullObjectValueTest.java
index 22e3434ea3..fa9dfa2669 100644
--- a/src/test/java/com/google/api/generator/engine/ast/NullObjectValueTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/NullObjectValueTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.engine.ast;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
 
diff --git a/src/test/java/com/google/api/generator/engine/ast/PrimitiveValueTest.java b/src/test/java/com/google/api/generator/engine/ast/PrimitiveValueTest.java
index 9c2f034d4c..37c3ae9cc4 100644
--- a/src/test/java/com/google/api/generator/engine/ast/PrimitiveValueTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/PrimitiveValueTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.engine.ast;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import com.google.api.generator.engine.ast.TypeNode.TypeKind;
diff --git a/src/test/java/com/google/api/generator/engine/ast/ReferenceTest.java b/src/test/java/com/google/api/generator/engine/ast/ReferenceTest.java
index 4fb0dca02d..b4e4b43496 100644
--- a/src/test/java/com/google/api/generator/engine/ast/ReferenceTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/ReferenceTest.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 
 import java.util.Arrays;
 import java.util.HashMap;
diff --git a/src/test/java/com/google/api/generator/engine/ast/ThrowExprTest.java b/src/test/java/com/google/api/generator/engine/ast/ThrowExprTest.java
index 48202e8552..cc4b38f3df 100644
--- a/src/test/java/com/google/api/generator/engine/ast/ThrowExprTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/ThrowExprTest.java
@@ -14,6 +14,7 @@
 
 package com.google.api.generator.engine.ast;
 
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import org.junit.Test;
@@ -24,7 +25,24 @@ public void createThrowExpr_basic() {
     TypeNode npeType = TypeNode.withExceptionClazz(NullPointerException.class);
     ThrowExpr.builder().setType(npeType).build();
     // No exception thrown, we're good.
+  }
 
+  @Test
+  public void createThrowExpr_basicExpr() {
+    TypeNode npeType = TypeNode.withExceptionClazz(NullPointerException.class);
+    VariableExpr throwVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                Variable.builder()
+                    .setName("e")
+                    .setType(TypeNode.withExceptionClazz(RuntimeException.class))
+                    .build())
+            .build();
+    ThrowExpr throwExpr = ThrowExpr.builder().setThrowExpr(throwVarExpr).build();
+    assertEquals(throwVarExpr.variable().type(), throwExpr.type());
+    // Setting the type doesn't matter.
+    throwExpr = ThrowExpr.builder().setThrowExpr(throwVarExpr).setType(npeType).build();
+    assertEquals(throwVarExpr.variable().type(), throwExpr.type());
   }
 
   @Test
@@ -62,4 +80,136 @@ public void createThrowExpr_badMessageExpr() {
         IllegalStateException.class,
         () -> ThrowExpr.builder().setType(npeType).setMessageExpr(messageExpr).build());
   }
+
+  @Test
+  public void createThrowExpr_causeExpr() {
+    TypeNode npeType =
+        TypeNode.withReference(ConcreteReference.withClazz(NullPointerException.class));
+    ThrowExpr.builder()
+        .setType(npeType)
+        .setCauseExpr(
+            NewObjectExpr.builder()
+                .setType(TypeNode.withReference(ConcreteReference.withClazz(Throwable.class)))
+                .build())
+        .build();
+    // Successfully created a ThrowExpr.
+  }
+
+  @Test
+  public void createThrowExpr_causeExpr_throwableSubtype() {
+    TypeNode npeType =
+        TypeNode.withReference(ConcreteReference.withClazz(NullPointerException.class));
+    ThrowExpr.builder()
+        .setType(npeType)
+        .setCauseExpr(
+            NewObjectExpr.builder()
+                .setType(TypeNode.withExceptionClazz(IllegalStateException.class))
+                .build())
+        .build();
+    // Successfully created a ThrowExpr.
+  }
+
+  @Test
+  public void createThrowExpr_causeExpr_onThrowableSubtype() {
+    TypeNode npeType =
+        TypeNode.withReference(ConcreteReference.withClazz(NullPointerException.class));
+    assertThrows(
+        IllegalStateException.class,
+        () ->
+            ThrowExpr.builder()
+                .setType(npeType)
+                .setCauseExpr(NewObjectExpr.builder().setType(TypeNode.STRING).build())
+                .build());
+  }
+
+  @Test
+  public void createThrowExpr_messageAndCauseExpr() {
+    TypeNode npeType =
+        TypeNode.withReference(ConcreteReference.withClazz(NullPointerException.class));
+    Expr messageExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("foobar")
+            .setReturnType(TypeNode.STRING)
+            .build();
+    ThrowExpr.builder()
+        .setType(npeType)
+        .setMessageExpr(messageExpr)
+        .setCauseExpr(
+            NewObjectExpr.builder()
+                .setType(TypeNode.withReference(ConcreteReference.withClazz(Throwable.class)))
+                .build())
+        .build();
+    // Successfully created a ThrowExpr.
+  }
+
+  @Test
+  public void createThrowExpr_cannotThrowVariableDeclaration() {
+    VariableExpr throwVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                Variable.builder()
+                    .setName("e")
+                    .setType(TypeNode.withExceptionClazz(RuntimeException.class))
+                    .build())
+            .build();
+    assertThrows(
+        IllegalStateException.class,
+        () ->
+            ThrowExpr.builder()
+                .setThrowExpr(throwVarExpr.toBuilder().setIsDecl(true).build())
+                .build());
+  }
+
+  @Test
+  public void createThrowExpr_cannotThrowNonExceptionTypedExpr() {
+    VariableExpr throwVarExpr =
+        VariableExpr.builder()
+            .setVariable(Variable.builder().setName("str").setType(TypeNode.STRING).build())
+            .build();
+    assertThrows(
+        IllegalStateException.class, () -> ThrowExpr.builder().setThrowExpr(throwVarExpr).build());
+  }
+
+  @Test
+  public void createThrowExpr_cannotHaveThrowVariableAndMessageExprPresent() {
+    Expr messageExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("foobar")
+            .setReturnType(TypeNode.STRING)
+            .build();
+    VariableExpr throwVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                Variable.builder()
+                    .setName("e")
+                    .setType(TypeNode.withExceptionClazz(RuntimeException.class))
+                    .build())
+            .build();
+    assertThrows(
+        IllegalStateException.class,
+        () -> ThrowExpr.builder().setThrowExpr(throwVarExpr).setMessageExpr(messageExpr).build());
+  }
+
+  @Test
+  public void createThrowExpr_cannotHaveThrowVariableAndCauseExprPresent() {
+    VariableExpr throwVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                Variable.builder()
+                    .setName("e")
+                    .setType(TypeNode.withExceptionClazz(RuntimeException.class))
+                    .build())
+            .build();
+    assertThrows(
+        IllegalStateException.class,
+        () ->
+            ThrowExpr.builder()
+                .setThrowExpr(throwVarExpr)
+                .setCauseExpr(
+                    NewObjectExpr.builder()
+                        .setType(
+                            TypeNode.withReference(ConcreteReference.withClazz(Throwable.class)))
+                        .build())
+                .build());
+  }
 }
diff --git a/src/test/java/com/google/api/generator/engine/ast/TryCatchStatementTest.java b/src/test/java/com/google/api/generator/engine/ast/TryCatchStatementTest.java
index db406aa9eb..9837c192f5 100644
--- a/src/test/java/com/google/api/generator/engine/ast/TryCatchStatementTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/TryCatchStatementTest.java
@@ -15,9 +15,11 @@
 package com.google.api.generator.engine.ast;
 
 import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import java.util.Arrays;
+import java.util.Collections;
 import org.junit.Test;
 
 public class TryCatchStatementTest {
@@ -32,9 +34,36 @@ public void validTryCatchStatement_simple() {
     TryCatchStatement tryCatch =
         TryCatchStatement.builder()
             .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
-            .setCatchVariableExpr(variableExpr)
+            .addCatch(variableExpr, Collections.emptyList())
             .build();
-    assertThat(tryCatch.catchVariableExpr()).isEqualTo(variableExpr);
+    assertEquals(1, tryCatch.catchVariableExprs().size());
+    assertThat(tryCatch.catchVariableExprs().get(0)).isEqualTo(variableExpr);
+  }
+
+  @Test
+  public void validTryCatchStatement_simpleMultiBlock() {
+    VariableExpr firstCatchVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                createVariable("e", TypeNode.withExceptionClazz(IllegalArgumentException.class)))
+            .setIsDecl(true)
+            .build();
+    VariableExpr secondCatchVarExpr =
+        VariableExpr.builder()
+            .setVariable(createVariable("e", TypeNode.withExceptionClazz(RuntimeException.class)))
+            .setIsDecl(true)
+            .build();
+
+    TryCatchStatement tryCatch =
+        TryCatchStatement.builder()
+            .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
+            .addCatch(firstCatchVarExpr, Collections.emptyList())
+            .addCatch(secondCatchVarExpr, Collections.emptyList())
+            .build();
+
+    assertEquals(2, tryCatch.catchVariableExprs().size());
+    assertThat(tryCatch.catchVariableExprs().get(0)).isEqualTo(firstCatchVarExpr);
+    assertThat(tryCatch.catchVariableExprs().get(1)).isEqualTo(secondCatchVarExpr);
   }
 
   @Test
@@ -49,41 +78,30 @@ public void validTryCatchStatement_withResources() {
         TryCatchStatement.builder()
             .setTryResourceExpr(assignmentExpr)
             .setTryBody(Arrays.asList(ExprStatement.withExpr(assignmentExpr)))
-            .setCatchVariableExpr(variableExpr)
+            .addCatch(variableExpr, Collections.emptyList())
             .build();
-    assertThat(tryCatch.catchVariableExpr()).isEqualTo(variableExpr);
+    assertThat(tryCatch.catchVariableExprs().get(0)).isEqualTo(variableExpr);
     assertThat(tryCatch.tryResourceExpr()).isEqualTo(assignmentExpr);
   }
 
   @Test
   public void validTryCatchStatement_sampleCode() {
-    Reference exceptionReference = ConcreteReference.withClazz(IllegalArgumentException.class);
-    TypeNode type = TypeNode.withReference(exceptionReference);
-    VariableExpr variableExpr =
-        VariableExpr.builder().setVariable(createVariable("e", type)).setIsDecl(true).build();
-
     TryCatchStatement tryCatch =
         TryCatchStatement.builder()
             .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
             .setIsSampleCode(true)
             .build();
-    assertThat(tryCatch.catchVariableExpr()).isNull();
+    assertThat(tryCatch.catchVariableExprs()).isEmpty();
   }
 
   @Test
   public void invalidTryCatchStatement_missingCatchVariable() {
-    Reference exceptionReference = ConcreteReference.withClazz(IllegalArgumentException.class);
-    TypeNode type = TypeNode.withReference(exceptionReference);
-    VariableExpr variableExpr =
-        VariableExpr.builder().setVariable(createVariable("e", type)).setIsDecl(true).build();
-
     assertThrows(
-        NullPointerException.class,
-        () -> {
-          TryCatchStatement.builder()
-              .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
-              .build();
-        });
+        IllegalStateException.class,
+        () ->
+            TryCatchStatement.builder()
+                .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
+                .build());
   }
 
   @Test
@@ -95,13 +113,11 @@ public void invalidTryCatchStatement_catchVariableNotDecl() {
 
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          TryCatchStatement tryCatch =
-              TryCatchStatement.builder()
-                  .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
-                  .setCatchVariableExpr(variableExpr)
-                  .build();
-        });
+        () ->
+            TryCatchStatement.builder()
+                .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
+                .addCatch(variableExpr, Collections.emptyList())
+                .build());
   }
 
   @Test
@@ -113,13 +129,11 @@ public void invalidTryCatchStatement_nonExceptionReference() {
 
     assertThrows(
         IllegalStateException.class,
-        () -> {
-          TryCatchStatement tryCatch =
-              TryCatchStatement.builder()
-                  .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
-                  .setCatchVariableExpr(variableExpr)
-                  .build();
-        });
+        () ->
+            TryCatchStatement.builder()
+                .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
+                .addCatch(variableExpr, Collections.emptyList())
+                .build());
   }
 
   private static AssignmentExpr createAssignmentExpr() {
diff --git a/src/test/java/com/google/api/generator/engine/ast/TypeNodeTest.java b/src/test/java/com/google/api/generator/engine/ast/TypeNodeTest.java
index 77c649e72f..5b80fdedc0 100644
--- a/src/test/java/com/google/api/generator/engine/ast/TypeNodeTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/TypeNodeTest.java
@@ -15,9 +15,9 @@
 package com.google.api.generator.engine.ast;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.ast.TypeNode.TypeKind;
 import java.util.Arrays;
diff --git a/src/test/java/com/google/api/generator/engine/ast/VaporReferenceTest.java b/src/test/java/com/google/api/generator/engine/ast/VaporReferenceTest.java
index c8a662fdc9..486bc2efab 100644
--- a/src/test/java/com/google/api/generator/engine/ast/VaporReferenceTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/VaporReferenceTest.java
@@ -14,9 +14,9 @@
 
 package com.google.api.generator.engine.ast;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 
@@ -52,7 +52,6 @@ public void basic_isStaticImport() {
   public void basic_nested() {
     String pkg = "com.google.example.examples.library.v1";
     String name = "Charles";
-    String enclosingClassName = "Babbage";
     Reference ref =
         VaporReference.builder()
             .setEnclosingClassNames("Babbage", "Ada")
diff --git a/src/test/java/com/google/api/generator/engine/ast/VariableTest.java b/src/test/java/com/google/api/generator/engine/ast/VariableTest.java
index 4f0b6c4743..b11cfd0662 100644
--- a/src/test/java/com/google/api/generator/engine/ast/VariableTest.java
+++ b/src/test/java/com/google/api/generator/engine/ast/VariableTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.engine.ast;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import com.google.api.generator.engine.ast.TypeNode.TypeKind;
diff --git a/src/test/java/com/google/api/generator/engine/writer/ImportWriterVisitorTest.java b/src/test/java/com/google/api/generator/engine/writer/ImportWriterVisitorTest.java
index 47a63ea6ee..07be47a996 100644
--- a/src/test/java/com/google/api/generator/engine/writer/ImportWriterVisitorTest.java
+++ b/src/test/java/com/google/api/generator/engine/writer/ImportWriterVisitorTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.engine.writer;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.ast.AnnotationNode;
 import com.google.api.generator.engine.ast.AnonymousClassExpr;
@@ -58,6 +58,7 @@
 import com.google.common.base.Function;
 import com.google.common.base.Strings;
 import java.io.File;
+import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -448,6 +449,26 @@ public void writeThrowExprImports_basic() {
     assertEquals("import java.io.IOException;\n\n", writerVisitor.write());
   }
 
+  @Test
+  public void writeThrowExprImports_throwExpr() {
+    Expr exprToThrow =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(
+                TypeNode.withReference(ConcreteReference.withClazz(Statement.class)))
+            .setMethodName("createException")
+            .setReturnType(TypeNode.withExceptionClazz(Exception.class))
+            .build();
+
+    TypeNode ignoredExceptionType =
+        TypeNode.withReference(ConcreteReference.withClazz(IOException.class));
+    ThrowExpr throwExpr =
+        ThrowExpr.builder().setType(ignoredExceptionType).setThrowExpr(exprToThrow).build();
+    throwExpr.accept(writerVisitor);
+    assertEquals(
+        LineFormatter.lines("import com.google.api.generator.engine.ast.Statement;\n\n"),
+        writerVisitor.write());
+  }
+
   @Test
   public void writeThrowExprImports_messageExpr() {
     TypeNode npeType = TypeNode.withExceptionClazz(NullPointerException.class);
@@ -475,6 +496,42 @@ public void writeThrowExprImports_messageExpr() {
         writerVisitor.write());
   }
 
+  @Test
+  public void writeThrowExprImports_messageAndCauseExpr() {
+    TypeNode npeType = TypeNode.withExceptionClazz(NullPointerException.class);
+    Expr messageExpr =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(
+                TypeNode.withReference(ConcreteReference.withClazz(IfStatement.class)))
+            .setMethodName("conditionExpr")
+            .setReturnType(TypeNode.withReference(ConcreteReference.withClazz(Expr.class)))
+            .build();
+
+    messageExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(messageExpr)
+            .setMethodName("foobar")
+            .setReturnType(TypeNode.STRING)
+            .build();
+    ThrowExpr throwExpr =
+        ThrowExpr.builder()
+            .setType(npeType)
+            .setMessageExpr(messageExpr)
+            .setCauseExpr(
+                NewObjectExpr.builder()
+                    .setType(TypeNode.withExceptionClazz(FileNotFoundException.class))
+                    .build())
+            .build();
+
+    throwExpr.accept(writerVisitor);
+    assertEquals(
+        LineFormatter.lines(
+            "import com.google.api.generator.engine.ast.Expr;\n",
+            "import com.google.api.generator.engine.ast.IfStatement;\n",
+            "import java.io.FileNotFoundException;\n\n"),
+        writerVisitor.write());
+  }
+
   @Test
   public void writeInstanceofExprImports_basic() {
     TypeNode exprType = TypeNode.withReference(ConcreteReference.withClazz(Expr.class));
@@ -837,10 +894,6 @@ public void writeLambdaExprImports() {
   }
 
   /** =============================== HELPERS =============================== */
-  private static TypeNode createType(Class clazz) {
-    return TypeNode.withReference(ConcreteReference.withClazz(clazz));
-  }
-
   private static Variable createVariable(String variableName, TypeNode type) {
     return Variable.builder().setName(variableName).setType(type).build();
   }
diff --git a/src/test/java/com/google/api/generator/engine/writer/JavaWriterVisitorTest.java b/src/test/java/com/google/api/generator/engine/writer/JavaWriterVisitorTest.java
index ac1f515169..39e448a263 100644
--- a/src/test/java/com/google/api/generator/engine/writer/JavaWriterVisitorTest.java
+++ b/src/test/java/com/google/api/generator/engine/writer/JavaWriterVisitorTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.engine.writer;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.ast.AnnotationNode;
 import com.google.api.generator.engine.ast.AnonymousClassExpr;
@@ -73,6 +73,7 @@
 import com.google.common.base.Function;
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -333,7 +334,6 @@ public void writeVariableExpr_localFinalDecl() {
 
   @Test
   public void writeVariableExpr_scopedDecl() {
-    IdentifierNode identifier = IdentifierNode.builder().setName("x").build();
     Variable variable = Variable.builder().setName("x").setType(TypeNode.INT).build();
     VariableExpr expr =
         VariableExpr.builder()
@@ -348,7 +348,6 @@ public void writeVariableExpr_scopedDecl() {
 
   @Test
   public void writeVariableExpr_scopedStaticFinalDecl() {
-    IdentifierNode identifier = IdentifierNode.builder().setName("x").build();
     Variable variable = Variable.builder().setName("x").setType(TypeNode.BOOLEAN).build();
     VariableExpr expr =
         VariableExpr.builder()
@@ -365,7 +364,6 @@ public void writeVariableExpr_scopedStaticFinalDecl() {
 
   @Test
   public void writeVariableExpr_scopedStaticFinalVolatileDecl() {
-    IdentifierNode identifier = IdentifierNode.builder().setName("x").build();
     Variable variable = Variable.builder().setName("x").setType(TypeNode.BOOLEAN).build();
     VariableExpr expr =
         VariableExpr.builder()
@@ -643,9 +641,6 @@ public void writeJavaDocComment_specialChar() {
 
   @Test
   public void writeTernaryExpr_basic() {
-    Variable variable = Variable.builder().setName("x").setType(TypeNode.INT).build();
-    VariableExpr variableExpr = VariableExpr.builder().setVariable(variable).build();
-
     Variable conditionVariable =
         Variable.builder().setName("condition").setType(TypeNode.BOOLEAN).build();
     VariableExpr conditionExpr = VariableExpr.builder().setVariable(conditionVariable).build();
@@ -1031,6 +1026,21 @@ public void writeThrowExpr_basic() {
     assertEquals("throw new NullPointerException()", writerVisitor.write());
   }
 
+  @Test
+  public void writeThrowExpr_basicThrowExpr() {
+    Expr exprToThrow =
+        MethodInvocationExpr.builder()
+            .setStaticReferenceType(
+                TypeNode.withReference(ConcreteReference.withClazz(Statement.class)))
+            .setMethodName("createException")
+            .setReturnType(TypeNode.withExceptionClazz(Exception.class))
+            .build();
+
+    ThrowExpr throwExpr = ThrowExpr.builder().setThrowExpr(exprToThrow).build();
+    throwExpr.accept(writerVisitor);
+    assertEquals("throw Statement.createException()", writerVisitor.write());
+  }
+
   @Test
   public void writeThrowExpr_basicWithMessage() {
     TypeNode npeType =
@@ -1041,6 +1051,22 @@ public void writeThrowExpr_basicWithMessage() {
     assertEquals("throw new NullPointerException(\"Some message asdf\")", writerVisitor.write());
   }
 
+  @Test
+  public void writeThrowExpr_basicWithCause() {
+    TypeNode npeType =
+        TypeNode.withReference(ConcreteReference.withClazz(NullPointerException.class));
+    ThrowExpr throwExpr =
+        ThrowExpr.builder()
+            .setType(npeType)
+            .setCauseExpr(
+                NewObjectExpr.builder()
+                    .setType(TypeNode.withReference(ConcreteReference.withClazz(Throwable.class)))
+                    .build())
+            .build();
+    throwExpr.accept(writerVisitor);
+    assertEquals("throw new NullPointerException(new Throwable())", writerVisitor.write());
+  }
+
   @Test
   public void writeThrowExpr_messageExpr() {
     TypeNode npeType = TypeNode.withExceptionClazz(NullPointerException.class);
@@ -1055,6 +1081,29 @@ public void writeThrowExpr_messageExpr() {
     assertEquals("throw new NullPointerException(foobar())", writerVisitor.write());
   }
 
+  @Test
+  public void writeThrowExpr_messageAndCauseExpr() {
+    TypeNode npeType = TypeNode.withExceptionClazz(NullPointerException.class);
+    Expr messageExpr =
+        MethodInvocationExpr.builder()
+            .setMethodName("foobar")
+            .setReturnType(TypeNode.STRING)
+            .build();
+    ThrowExpr throwExpr =
+        ThrowExpr.builder()
+            .setType(npeType)
+            .setMessageExpr(messageExpr)
+            .setCauseExpr(
+                NewObjectExpr.builder()
+                    .setType(TypeNode.withReference(ConcreteReference.withClazz(Throwable.class)))
+                    .build())
+            .build();
+
+    throwExpr.accept(writerVisitor);
+    assertEquals(
+        "throw new NullPointerException(foobar(), new Throwable())", writerVisitor.write());
+  }
+
   @Test
   public void writeInstanceofExpr() {
     Variable variable = Variable.builder().setName("x").setType(TypeNode.STRING).build();
@@ -1415,7 +1464,7 @@ public void writeTryCatchStatement_simple() {
         TryCatchStatement.builder()
             .setTryBody(
                 Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("x", "3", TypeNode.INT))))
-            .setCatchVariableExpr(variableExpr)
+            .addCatch(variableExpr, Collections.emptyList())
             .build();
 
     tryCatch.accept(writerVisitor);
@@ -1426,6 +1475,72 @@ public void writeTryCatchStatement_simple() {
         writerVisitor.write());
   }
 
+  @Test
+  public void writeTryCatchStatement_simpleMultiCatch() {
+    VariableExpr firstCatchVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                createVariable("e", TypeNode.withExceptionClazz(IllegalArgumentException.class)))
+            .build();
+    VariableExpr secondCatchVarExpr =
+        VariableExpr.builder()
+            .setVariable(createVariable("e", TypeNode.withExceptionClazz(RuntimeException.class)))
+            .build();
+
+    TryCatchStatement tryCatch =
+        TryCatchStatement.builder()
+            .setTryBody(
+                Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("x", "3", TypeNode.INT))))
+            .addCatch(
+                firstCatchVarExpr.toBuilder().setIsDecl(true).build(), Collections.emptyList())
+            .addCatch(
+                secondCatchVarExpr.toBuilder().setIsDecl(true).build(), Collections.emptyList())
+            .build();
+
+    tryCatch.accept(writerVisitor);
+    assertEquals(
+        LineFormatter.lines(
+            "try {\n",
+            "int x = 3;\n",
+            "} catch (IllegalArgumentException e) {\n",
+            "} catch (RuntimeException e) {\n",
+            "}\n"),
+        writerVisitor.write());
+  }
+
+  @Test
+  public void writeTryCatchStatement_simpleMultiCatchOrderMatters() {
+    VariableExpr firstCatchVarExpr =
+        VariableExpr.builder()
+            .setVariable(
+                createVariable("e", TypeNode.withExceptionClazz(IllegalArgumentException.class)))
+            .build();
+    VariableExpr secondCatchVarExpr =
+        VariableExpr.builder()
+            .setVariable(createVariable("e", TypeNode.withExceptionClazz(RuntimeException.class)))
+            .build();
+
+    TryCatchStatement tryCatch =
+        TryCatchStatement.builder()
+            .setTryBody(
+                Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("x", "3", TypeNode.INT))))
+            .addCatch(
+                secondCatchVarExpr.toBuilder().setIsDecl(true).build(), Collections.emptyList())
+            .addCatch(
+                firstCatchVarExpr.toBuilder().setIsDecl(true).build(), Collections.emptyList())
+            .build();
+
+    tryCatch.accept(writerVisitor);
+    assertEquals(
+        LineFormatter.lines(
+            "try {\n",
+            "int x = 3;\n",
+            "} catch (RuntimeException e) {\n",
+            "} catch (IllegalArgumentException e) {\n",
+            "}\n"),
+        writerVisitor.write());
+  }
+
   @Test
   public void writeTryCatchStatement_withResources() {
     Reference exceptionReference = ConcreteReference.withClazz(IllegalArgumentException.class);
@@ -1438,8 +1553,8 @@ public void writeTryCatchStatement_withResources() {
             .setTryResourceExpr(createAssignmentExpr("aBool", "false", TypeNode.BOOLEAN))
             .setTryBody(
                 Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("y", "4", TypeNode.INT))))
-            .setCatchVariableExpr(variableExpr)
-            .setCatchBody(
+            .addCatch(
+                variableExpr,
                 Arrays.asList(
                     ExprStatement.withExpr(createAssignmentExpr("foobar", "123", TypeNode.INT))))
             .build();
@@ -1458,11 +1573,6 @@ public void writeTryCatchStatement_withResources() {
 
   @Test
   public void writeTryCatchStatement_sampleCodeNoCatch() {
-    Reference exceptionReference = ConcreteReference.withClazz(IllegalArgumentException.class);
-    TypeNode type = TypeNode.withReference(exceptionReference);
-    VariableExpr variableExpr =
-        VariableExpr.builder().setVariable(createVariable("e", type)).setIsDecl(true).build();
-
     TryCatchStatement tryCatch =
         TryCatchStatement.builder()
             .setTryBody(
@@ -1487,8 +1597,8 @@ public void writeTryCatchStatement_sampleCodeWithCatch() {
             .setTryResourceExpr(createAssignmentExpr("aBool", "false", TypeNode.BOOLEAN))
             .setTryBody(
                 Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("y", "4", TypeNode.INT))))
-            .setCatchVariableExpr(variableExpr)
-            .setCatchBody(
+            .addCatch(
+                variableExpr,
                 Arrays.asList(
                     ExprStatement.withExpr(createAssignmentExpr("foobar", "123", TypeNode.INT))))
             .build();
diff --git a/src/test/java/com/google/api/generator/gapic/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/BUILD.bazel
index 7c614e8093..5c5f8983ad 100644
--- a/src/test/java/com/google/api/generator/gapic/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/gapic/BUILD.bazel
@@ -4,6 +4,13 @@ filegroup(
     name = "gapic_files",
     srcs = [
         "//src/test/java/com/google/api/generator/gapic/composer:composer_files",
+        "//src/test/java/com/google/api/generator/gapic/composer/defaultvalue:defaultvalue_files",
+        "//src/test/java/com/google/api/generator/gapic/composer/grpc:grpc_files",
+        #        "//src/test/java/com/google/api/generator/gapic/composer/grpcrest:grpcrest_files",
+        "//src/test/java/com/google/api/generator/gapic/composer/resourcename:resourcename_files",
+        "//src/test/java/com/google/api/generator/gapic/composer/rest:rest_files",
+        "//src/test/java/com/google/api/generator/gapic/composer/samplecode:samplecode_files",
+        "//src/test/java/com/google/api/generator/gapic/composer/utils:utils_files",
         "//src/test/java/com/google/api/generator/gapic/model:model_files",
         "//src/test/java/com/google/api/generator/gapic/protoparser:protoparser_files",
         "//src/test/java/com/google/api/generator/gapic/utils:utils_files",
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/composer/common/BUILD.bazel
index 1d8c68ad72..28a4bfc8b4 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/gapic/composer/common/BUILD.bazel
@@ -5,8 +5,6 @@ package(default_visibility = ["//visibility:public"])
 
 UPDATE_GOLDENS_TESTS = [
     "BatchingDescriptorComposerTest",
-    "ServiceClientClassComposerTest",
-    "ServiceStubClassComposerTest",
 ]
 
 TESTS = UPDATE_GOLDENS_TESTS + [
@@ -29,6 +27,7 @@ TEST_DEPS = [
     "//src/main/java/com/google/api/generator/gapic/protoparser",
     "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue",
     "//src/test/java/com/google/api/generator/gapic/testdata:deprecated_service_java_proto",
+    "//src/test/java/com/google/api/generator/gapic/testdata:bookshop_java_proto",
     "//src/test/java/com/google/api/generator/gapic/testdata:showcase_java_proto",
     "//src/test/java/com/google/api/generator/gapic/testdata:testgapic_java_proto",
     "@com_google_api_api_common//jar",
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposerTest.java
index f2ac7a5da5..50fdf0fac3 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/common/BatchingDescriptorComposerTest.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.gapic.composer.common;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.ast.Expr;
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposerTest.java
index 09b1bf5b1c..598f261f8a 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/common/RetrySettingsComposerTest.java
@@ -15,8 +15,8 @@
 package com.google.api.generator.gapic.composer.common;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.gax.rpc.StatusCode;
 import com.google.api.generator.engine.ast.BlockStatement;
@@ -27,6 +27,7 @@
 import com.google.api.generator.engine.ast.Variable;
 import com.google.api.generator.engine.ast.VariableExpr;
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.composer.grpc.GrpcContext;
 import com.google.api.generator.gapic.model.GapicBatchingSettings;
 import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.GapicServiceConfig;
@@ -41,7 +42,6 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.showcase.v1beta1.EchoOuterClass;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -141,7 +141,6 @@ public void paramDefinitionsBlock_basic() {
   @Test
   public void codesDefinitionsBlock_noConfigsFound() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
@@ -178,7 +177,6 @@ public void codesDefinitionsBlock_noConfigsFound() {
   @Test
   public void codesDefinitionsBlock_basic() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
@@ -218,7 +216,6 @@ public void codesDefinitionsBlock_basic() {
   @Test
   public void simpleBuilderExpr_basic() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
@@ -300,7 +297,6 @@ public void simpleBuilderExpr_basic() {
   @Test
   public void lroBuilderExpr() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
@@ -329,7 +325,9 @@ public void lroBuilderExpr() {
             waitMethod,
             builderVarExpr,
             RETRY_CODES_DEFINITIONS_VAR_EXPR,
-            RETRY_PARAM_DEFINITIONS_VAR_EXPR);
+            RETRY_PARAM_DEFINITIONS_VAR_EXPR,
+            GrpcContext.instance().operationResponseTransformerType(),
+            GrpcContext.instance().operationMetadataTransformerType());
     builderExpr.accept(writerVisitor);
     String expected =
         LineFormatter.lines(
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/TestProtoLoader.java b/src/test/java/com/google/api/generator/gapic/composer/common/TestProtoLoader.java
index 5cd4ade9da..e9eb95721d 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/TestProtoLoader.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/common/TestProtoLoader.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.gapic.composer.common;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.gapic.model.GapicBatchingSettings;
 import com.google.api.generator.gapic.model.GapicContext;
@@ -27,6 +27,7 @@
 import com.google.api.generator.gapic.protoparser.BatchingSettingsConfigParser;
 import com.google.api.generator.gapic.protoparser.Parser;
 import com.google.api.generator.gapic.protoparser.ServiceConfigParser;
+import com.google.bookshop.v1beta1.BookshopProto;
 import com.google.logging.v2.LogEntryProto;
 import com.google.logging.v2.LoggingConfigProto;
 import com.google.logging.v2.LoggingMetricsProto;
@@ -51,8 +52,7 @@
 
 public class TestProtoLoader {
   private static final TestProtoLoader INSTANCE =
-      new TestProtoLoader(
-          Transport.GRPC, "src/test/java/com/google/api/generator/gapic/testdata/");
+      new TestProtoLoader(Transport.GRPC, "src/test/java/com/google/api/generator/gapic/testdata/");
   private final String testFilesDirectory;
   private final Transport transport;
 
@@ -93,6 +93,34 @@ public GapicContext parseDeprecatedService() {
         .build();
   }
 
+  public GapicContext parseBookshopService() {
+    FileDescriptor fileDescriptor = BookshopProto.getDescriptor();
+    ServiceDescriptor serviceDescriptor = fileDescriptor.getServices().get(0);
+    assertEquals(serviceDescriptor.getName(), "Bookshop");
+
+    Map<String, Message> messageTypes = Parser.parseMessages(fileDescriptor);
+    Map<String, ResourceName> resourceNames = new HashMap<>();
+    Set<ResourceName> outputResourceNames = new HashSet<>();
+    List<Service> services =
+        Parser.parseService(
+            fileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
+
+    String jsonFilename = "bookshop_grpc_service_config.json";
+    Path jsonPath = Paths.get(testFilesDirectory, jsonFilename);
+    Optional<GapicServiceConfig> configOpt = ServiceConfigParser.parse(jsonPath.toString());
+    assertTrue(configOpt.isPresent());
+    GapicServiceConfig config = configOpt.get();
+
+    return GapicContext.builder()
+        .setMessages(messageTypes)
+        .setResourceNames(resourceNames)
+        .setServices(services)
+        .setServiceConfig(config)
+        .setHelperResourceNames(outputResourceNames)
+        .setTransport(transport)
+        .build();
+  }
+
   public GapicContext parseShowcaseEcho() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
     ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
@@ -268,4 +296,8 @@ public GapicContext parseLogging() {
   public String getTestFilesDirectory() {
     return testFilesDirectory;
   }
+
+  public Transport getTransport() {
+    return transport;
+  }
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/constants/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/composer/constants/BUILD.bazel
deleted file mode 100644
index e69de29bb2..0000000000
diff --git a/src/test/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposerTest.java
index 6a60b91e5d..cf444a270d 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/defaultvalue/DefaultValueComposerTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.gapic.composer.defaultvalue;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.Expr;
@@ -24,6 +24,7 @@
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.protoparser.Parser;
+import com.google.api.generator.testutils.LineFormatter;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.showcase.v1beta1.EchoOuterClass;
@@ -222,8 +223,8 @@ public void defaultValue_wildcardResourceNameWithOnlyDeletedTopic() {
   }
 
   @Test
-  public void defaultValue_resourceNameWithOnlyWildcards() {
-    // Edge case that should never happen in practice.
+  public void defaultValue_resourceNameWithOnlyWildcards_valueOnly() {
+    // Edge case that occurs in GCS.
     // Wildcard, but the resource names map has only other names that contain only the deleted-topic
     // constant.
     FileDescriptor lockerServiceFileDescriptor = LockerProto.getDescriptor();
@@ -233,13 +234,50 @@ public void defaultValue_resourceNameWithOnlyWildcards() {
         typeStringsToResourceNames.get("cloudresourcemanager.googleapis.com/Anything");
     String fallbackField = "foobar";
     Expr expr =
-        DefaultValueComposer.createDefaultValue(
-            resourceName, Collections.emptyList(), fallbackField);
+        DefaultValueComposer.createDefaultValueResourceHelper(
+            resourceName,
+            Collections.emptyList(),
+            fallbackField,
+            /* allowAnonResourceNameClass = */ false);
     expr.accept(writerVisitor);
     assertEquals(
         String.format("\"%s%s\"", fallbackField, fallbackField.hashCode()), writerVisitor.write());
   }
 
+  @Test
+  public void defaultValue_resourceNameWithOnlyWildcards_allowAnonResourceNameClass() {
+    // Edge case that occurs in GCS.
+    // Wildcard, but the resource names map has only other names that contain only the deleted-topic
+    // constant.
+    FileDescriptor lockerServiceFileDescriptor = LockerProto.getDescriptor();
+    Map<String, ResourceName> typeStringsToResourceNames =
+        Parser.parseResourceNames(lockerServiceFileDescriptor);
+    ResourceName resourceName =
+        typeStringsToResourceNames.get("cloudresourcemanager.googleapis.com/Anything");
+    String fallbackField = "foobar";
+    Expr expr =
+        DefaultValueComposer.createDefaultValue(
+            resourceName, Collections.emptyList(), fallbackField);
+    expr.accept(writerVisitor);
+    String expected =
+        LineFormatter.lines(
+            "new ResourceName() {\n",
+            "@Override\n",
+            "public Map<String, String> getFieldValuesMap() {\n",
+            "Map<String, String> fieldValuesMap = new HashMap<>();\n",
+            "fieldValuesMap.put(\"foobar\", \"foobar-1268878963\");\n",
+            "return fieldValuesMap;\n",
+            "}\n",
+            "\n",
+            "@Override\n",
+            "public String getFieldValue(String fieldName) {\n",
+            "return getFieldValuesMap().get(fieldName);\n",
+            "}\n",
+            "\n",
+            "}");
+    assertEquals(expected, writerVisitor.write());
+  }
+
   @Test
   public void createSimpleMessage_basicPrimitivesOnly() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
@@ -307,4 +345,28 @@ public void createSimpleMessage_onlyOneofs() {
     expr.accept(writerVisitor);
     assertEquals("WaitRequest.newBuilder().build()", writerVisitor.write());
   }
+
+  @Test
+  public void createAnonymousResourceNameClass() {
+    Expr expr = DefaultValueComposer.createAnonymousResourceNameClass("resource");
+    expr.accept(writerVisitor);
+    String expected =
+        LineFormatter.lines(
+            "new ResourceName() {\n",
+            "@Override\n",
+            "public Map<String, String> getFieldValuesMap() {\n",
+            "Map<String, String> fieldValuesMap = new HashMap<>();\n",
+            "fieldValuesMap.put(\"resource\", \"resource-341064690\");\n",
+            "return fieldValuesMap;\n",
+            "}\n",
+            "\n",
+            "@Override\n",
+            "public String getFieldValue(String fieldName) {\n",
+            "return getFieldValuesMap().get(fieldName);\n",
+            "}\n",
+            "\n",
+            "}");
+
+    assertEquals(expected, writerVisitor.write());
+  }
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/composer/grpc/BUILD.bazel
index 8c0cabe5a1..825635a75e 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/BUILD.bazel
@@ -8,8 +8,10 @@ TESTS = [
     "GrpcServiceStubClassComposerTest",
     "MockServiceClassComposerTest",
     "MockServiceImplClassComposerTest",
+    "ServiceClientClassComposerTest",
     "ServiceClientTestClassComposerTest",
     "ServiceSettingsClassComposerTest",
+    "ServiceStubClassComposerTest",
     "ServiceStubSettingsClassComposerTest",
 ]
 
@@ -33,9 +35,7 @@ TEST_DEPS = [
     "//src/main/java/com/google/api/generator/gapic/model",
     "//src/main/java/com/google/api/generator/gapic/protoparser",
     "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue",
-    "//src/test/java/com/google/api/generator/gapic/testdata:deprecated_service_java_proto",
     "//src/test/java/com/google/api/generator/gapic/testdata:showcase_java_proto",
-    "//src/test/java/com/google/api/generator/gapic/testdata:testgapic_java_proto",
     "@com_google_api_api_common//jar",
     "@com_google_api_gax_java//gax",
     "@com_google_api_api_common",
@@ -49,17 +49,10 @@ TEST_DEPS = [
 ]
 
 filegroup(
-    name = "composer_files",
+    name = "grpc_files",
     srcs = glob(["*.java"]),
 )
 
-java_proto_library(
-    name = "pubsub_java_proto",
-    deps = [
-        "@com_google_googleapis//google/pubsub/v1:pubsub_proto",
-    ],
-)
-
 java_proto_library(
     name = "common_resources_java_proto",
     deps = [
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposerTest.java
index 8ccbc442ed..9bdb460f96 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/GrpcServiceStubClassComposerTest.java
@@ -62,8 +62,7 @@ public void generateGrpcServiceStubClass_httpBindings() {
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
     Utils.saveCodegenToFile(this.getClass(), "GrpcTestingStub.golden", visitor.write());
-    Path goldenFilePath =
-        Paths.get(Utils.getGoldenDir(this.getClass()), "GrpcTestingStub.golden");
+    Path goldenFilePath = Paths.get(Utils.getGoldenDir(this.getClass()), "GrpcTestingStub.golden");
     Assert.assertCodeEquals(goldenFilePath, visitor.write());
   }
 
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/ServiceClientClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientClassComposerTest.java
similarity index 71%
rename from src/test/java/com/google/api/generator/gapic/composer/common/ServiceClientClassComposerTest.java
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientClassComposerTest.java
index 3510efaf3f..331b94e484 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/ServiceClientClassComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientClassComposerTest.java
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.api.generator.gapic.composer.common;
+package com.google.api.generator.gapic.composer.grpc;
 
 import static com.google.api.generator.test.framework.Assert.assertCodeEquals;
 
@@ -28,7 +28,7 @@
 public class ServiceClientClassComposerTest {
   @Test
   public void generateServiceClasses() {
-    GapicContext context = TestProtoLoader.instance().parseShowcaseEcho();
+    GapicContext context = GrpcTestProtoLoader.instance().parseShowcaseEcho();
     Service echoProtoService = context.services().get(0);
     GapicClass clazz = ServiceClientClassComposer.instance().generate(context, echoProtoService);
 
@@ -41,7 +41,7 @@ public void generateServiceClasses() {
 
   @Test
   public void generateServiceClasses_deprecated() {
-    GapicContext context = TestProtoLoader.instance().parseDeprecatedService();
+    GapicContext context = GrpcTestProtoLoader.instance().parseDeprecatedService();
     Service protoService = context.services().get(0);
     GapicClass clazz = ServiceClientClassComposer.instance().generate(context, protoService);
 
@@ -55,15 +55,27 @@ public void generateServiceClasses_deprecated() {
 
   @Test
   public void generateServiceClasses_methodSignatureHasNestedFields() {
-    GapicContext context = TestProtoLoader.instance().parseShowcaseIdentity();
+    GapicContext context = GrpcTestProtoLoader.instance().parseShowcaseIdentity();
     Service protoService = context.services().get(0);
     GapicClass clazz = ServiceClientClassComposer.instance().generate(context, protoService);
 
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
     Utils.saveCodegenToFile(this.getClass(), "IdentityClient.golden", visitor.write());
-    Path goldenFilePath =
-        Paths.get(Utils.getGoldenDir(this.getClass()), "IdentityClient.golden");
+    Path goldenFilePath = Paths.get(Utils.getGoldenDir(this.getClass()), "IdentityClient.golden");
+    assertCodeEquals(goldenFilePath, visitor.write());
+  }
+
+  @Test
+  public void generateServiceClasses_bookshopNameConflicts() {
+    GapicContext context = GrpcTestProtoLoader.instance().parseBookshopService();
+    Service protoService = context.services().get(0);
+    GapicClass clazz = ServiceClientClassComposer.instance().generate(context, protoService);
+
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    Utils.saveCodegenToFile(this.getClass(), "BookshopClient.golden", visitor.write());
+    Path goldenFilePath = Paths.get(Utils.getGoldenDir(this.getClass()), "BookshopClient.golden");
     assertCodeEquals(goldenFilePath, visitor.write());
   }
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposerTest.java
index cbb6bae23b..9874286d82 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceClientTestClassComposerTest.java
@@ -15,10 +15,9 @@
 package com.google.api.generator.gapic.composer.grpc;
 
 import static com.google.api.generator.test.framework.Assert.assertCodeEquals;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
-import com.google.api.generator.gapic.composer.common.ServiceClientClassComposer;
 import com.google.api.generator.gapic.model.GapicClass;
 import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.Service;
@@ -38,8 +37,7 @@ public void generateClientTest_echoClient() {
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
     Utils.saveCodegenToFile(this.getClass(), "EchoClientTest.golden", visitor.write());
-    Path goldenFilePath =
-        Paths.get(Utils.getGoldenDir(this.getClass()), "EchoClientTest.golden");
+    Path goldenFilePath = Paths.get(Utils.getGoldenDir(this.getClass()), "EchoClientTest.golden");
     assertCodeEquals(goldenFilePath, visitor.write());
   }
 
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/ServiceStubClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubClassComposerTest.java
similarity index 94%
rename from src/test/java/com/google/api/generator/gapic/composer/common/ServiceStubClassComposerTest.java
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubClassComposerTest.java
index b30ce3630c..bb411b9ad3 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/ServiceStubClassComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubClassComposerTest.java
@@ -12,9 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.api.generator.gapic.composer.common;
+package com.google.api.generator.gapic.composer.grpc;
 
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.composer.common.TestProtoLoader;
 import com.google.api.generator.gapic.model.GapicClass;
 import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.Service;
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposerTest.java
index 3a907c432f..468c2d8219 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/ServiceStubSettingsClassComposerTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.gapic.composer.grpc;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
 import com.google.api.generator.gapic.model.GapicClass;
@@ -67,8 +67,7 @@ public void generateServiceStubSettingsClasses_basic() {
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
     Utils.saveCodegenToFile(this.getClass(), "EchoStubSettings.golden", visitor.write());
-    Path goldenFilePath =
-        Paths.get(Utils.getGoldenDir(this.getClass()), "EchoStubSettings.golden");
+    Path goldenFilePath = Paths.get(Utils.getGoldenDir(this.getClass()), "EchoStubSettings.golden");
     Assert.assertCodeEquals(goldenFilePath, visitor.write());
   }
 
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/BookshopClient.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/BookshopClient.golden
new file mode 100644
index 0000000000..069bd7a634
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/BookshopClient.golden
@@ -0,0 +1,242 @@
+package com.google.bookshop.v1beta1;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.bookshop.v1beta1.stub.BookshopStub;
+import com.google.bookshop.v1beta1.stub.BookshopStubSettings;
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * This class provides the ability to make remote calls to the backing service through method calls
+ * that map to API methods. Sample code to get started:
+ *
+ * <pre>{@code
+ * try (BookshopClient bookshopClient = BookshopClient.create()) {
+ *   int booksCount = 1618425911;
+ *   List<Book> books = new ArrayList<>();
+ *   Book response = bookshopClient.getBook(booksCount, books);
+ * }
+ * }</pre>
+ *
+ * <p>Note: close() needs to be called on the BookshopClient object to clean up resources such as
+ * threads. In the example above, try-with-resources is used, which automatically calls close().
+ *
+ * <p>The surface of this class includes several types of Java methods for each of the API's
+ * methods:
+ *
+ * <ol>
+ *   <li>A "flattened" method. With this type of method, the fields of the request type have been
+ *       converted into function parameters. It may be the case that not all fields are available as
+ *       parameters, and not every API method will have a flattened method entry point.
+ *   <li>A "request object" method. This type of method only takes one parameter, a request object,
+ *       which must be constructed before the call. Not every API method will have a request object
+ *       method.
+ *   <li>A "callable" method. This type of method takes no parameters and returns an immutable API
+ *       callable object, which can be used to initiate calls to the service.
+ * </ol>
+ *
+ * <p>See the individual methods for example code.
+ *
+ * <p>Many parameters require resource names to be formatted in a particular way. To assist with
+ * these names, this class includes a format method for each type of name, and additionally a parse
+ * method to extract the individual identifiers contained within names that are returned.
+ *
+ * <p>This class can be customized by passing in a custom instance of BookshopSettings to create().
+ * For example:
+ *
+ * <p>To customize credentials:
+ *
+ * <pre>{@code
+ * BookshopSettings bookshopSettings =
+ *     BookshopSettings.newBuilder()
+ *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
+ *         .build();
+ * BookshopClient bookshopClient = BookshopClient.create(bookshopSettings);
+ * }</pre>
+ *
+ * <p>To customize the endpoint:
+ *
+ * <pre>{@code
+ * BookshopSettings bookshopSettings =
+ *     BookshopSettings.newBuilder().setEndpoint(myEndpoint).build();
+ * BookshopClient bookshopClient = BookshopClient.create(bookshopSettings);
+ * }</pre>
+ *
+ * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
+ */
+@BetaApi
+@Generated("by gapic-generator-java")
+public class BookshopClient implements BackgroundResource {
+  private final BookshopSettings settings;
+  private final BookshopStub stub;
+
+  /** Constructs an instance of BookshopClient with default settings. */
+  public static final BookshopClient create() throws IOException {
+    return create(BookshopSettings.newBuilder().build());
+  }
+
+  /**
+   * Constructs an instance of BookshopClient, using the given settings. The channels are created
+   * based on the settings passed in, or defaults for any settings that are not set.
+   */
+  public static final BookshopClient create(BookshopSettings settings) throws IOException {
+    return new BookshopClient(settings);
+  }
+
+  /**
+   * Constructs an instance of BookshopClient, using the given stub for making calls. This is for
+   * advanced usage - prefer using create(BookshopSettings).
+   */
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public static final BookshopClient create(BookshopStub stub) {
+    return new BookshopClient(stub);
+  }
+
+  /**
+   * Constructs an instance of BookshopClient, using the given settings. This is protected so that
+   * it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
+   */
+  protected BookshopClient(BookshopSettings settings) throws IOException {
+    this.settings = settings;
+    this.stub = ((BookshopStubSettings) settings.getStubSettings()).createStub();
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  protected BookshopClient(BookshopStub stub) {
+    this.settings = null;
+    this.stub = stub;
+  }
+
+  public final BookshopSettings getSettings() {
+    return settings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public BookshopStub getStub() {
+    return stub;
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (BookshopClient bookshopClient = BookshopClient.create()) {
+   *   int booksCount = 1618425911;
+   *   List<Book> books = new ArrayList<>();
+   *   Book response = bookshopClient.getBook(booksCount, books);
+   * }
+   * }</pre>
+   *
+   * @param booksCount
+   * @param books
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Book getBook(int booksCount, List<Book> books) {
+    GetBookRequest request =
+        GetBookRequest.newBuilder().setBooksCount(booksCount).addAllBooks(books).build();
+    return getBook(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (BookshopClient bookshopClient = BookshopClient.create()) {
+   *   String booksList = "booksList2-1119589686";
+   *   List<Book> books = new ArrayList<>();
+   *   Book response = bookshopClient.getBook(booksList, books);
+   * }
+   * }</pre>
+   *
+   * @param booksList
+   * @param books
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Book getBook(String booksList, List<Book> books) {
+    GetBookRequest request =
+        GetBookRequest.newBuilder().setBooksList(booksList).addAllBooks(books).build();
+    return getBook(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (BookshopClient bookshopClient = BookshopClient.create()) {
+   *   GetBookRequest request =
+   *       GetBookRequest.newBuilder()
+   *           .setBooksCount1(1618425911)
+   *           .setBooksList2("booksList2-1119589686")
+   *           .addAllBooks3(new ArrayList<Book>())
+   *           .build();
+   *   Book response = bookshopClient.getBook(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Book getBook(GetBookRequest request) {
+    return getBookCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (BookshopClient bookshopClient = BookshopClient.create()) {
+   *   GetBookRequest request =
+   *       GetBookRequest.newBuilder()
+   *           .setBooksCount1(1618425911)
+   *           .setBooksList2("booksList2-1119589686")
+   *           .addAllBooks3(new ArrayList<Book>())
+   *           .build();
+   *   ApiFuture<Book> future = bookshopClient.getBookCallable().futureCall(request);
+   *   // Do something.
+   *   Book response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<GetBookRequest, Book> getBookCallable() {
+    return stub.getBookCallable();
+  }
+
+  @Override
+  public final void close() {
+    stub.close();
+  }
+
+  @Override
+  public void shutdown() {
+    stub.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return stub.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return stub.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    stub.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return stub.awaitTermination(duration, unit);
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/DeprecatedServiceClient.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceClient.golden
similarity index 100%
rename from src/test/java/com/google/api/generator/gapic/composer/common/goldens/DeprecatedServiceClient.golden
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceClient.golden
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceClientTest.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceClientTest.golden
index bf7356d98c..5e26ce1290 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceClientTest.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceClientTest.golden
@@ -26,8 +26,8 @@ import org.junit.Test;
 public class DeprecatedServiceClientTest {
   private static MockDeprecatedService mockDeprecatedService;
   private static MockServiceHelper mockServiceHelper;
-  private DeprecatedServiceClient client;
   private LocalChannelProvider channelProvider;
+  private DeprecatedServiceClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceSettings.golden
index 34d39be82a..5e61122577 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceSettings.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceSettings.golden
@@ -155,14 +155,13 @@ public class DeprecatedServiceSettings extends ClientSettings<DeprecatedServiceS
       return ((DeprecatedServiceStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/DeprecatedServiceStub.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStub.golden
similarity index 100%
rename from src/test/java/com/google/api/generator/gapic/composer/common/goldens/DeprecatedServiceStub.golden
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStub.golden
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStubSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStubSettings.golden
index 6e44ff4bd2..899b03bbce 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStubSettings.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/DeprecatedServiceStubSettings.golden
@@ -108,6 +108,11 @@ public class DeprecatedServiceStubSettings extends StubSettings<DeprecatedServic
     return "localhost:7469";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "localhost:7469";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -115,7 +120,9 @@ public class DeprecatedServiceStubSettings extends StubSettings<DeprecatedServic
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -225,6 +232,8 @@ public class DeprecatedServiceStubSettings extends StubSettings<DeprecatedServic
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -243,14 +252,13 @@ public class DeprecatedServiceStubSettings extends StubSettings<DeprecatedServic
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/EchoClient.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClient.golden
similarity index 94%
rename from src/test/java/com/google/api/generator/gapic/composer/common/goldens/EchoClient.golden
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClient.golden
index 5791d9086d..3e6735f6bd 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/EchoClient.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClient.golden
@@ -1,6 +1,5 @@
 package com.google.showcase.v1beta1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -769,6 +768,53 @@ public class EchoClient implements BackgroundResource {
     return stub.blockCallable();
   }
 
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (EchoClient echoClient = EchoClient.create()) {
+   *   EchoRequest request =
+   *       EchoRequest.newBuilder()
+   *           .setName(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setParent(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setSeverity(Severity.forNumber(0))
+   *           .setFoobar(Foobar.newBuilder().build())
+   *           .build();
+   *   Object response = echoClient.collideName(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Object collideName(EchoRequest request) {
+    return collideNameCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Sample code:
+   *
+   * <pre>{@code
+   * try (EchoClient echoClient = EchoClient.create()) {
+   *   EchoRequest request =
+   *       EchoRequest.newBuilder()
+   *           .setName(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setParent(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+   *           .setSeverity(Severity.forNumber(0))
+   *           .setFoobar(Foobar.newBuilder().build())
+   *           .build();
+   *   ApiFuture<Object> future = echoClient.collideNameCallable().futureCall(request);
+   *   // Do something.
+   *   Object response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<EchoRequest, Object> collideNameCallable() {
+    return stub.collideNameCallable();
+  }
+
   @Override
   public final void close() {
     stub.close();
@@ -813,14 +859,7 @@ public class EchoClient implements BackgroundResource {
       ApiFuture<PagedExpandPage> futurePage =
           PagedExpandPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<PagedExpandPage, PagedExpandPagedResponse>() {
-            @Override
-            public PagedExpandPagedResponse apply(PagedExpandPage input) {
-              return new PagedExpandPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new PagedExpandPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private PagedExpandPagedResponse(PagedExpandPage page) {
@@ -894,12 +933,7 @@ public class EchoClient implements BackgroundResource {
           SimplePagedExpandPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<SimplePagedExpandPage, SimplePagedExpandPagedResponse>() {
-            @Override
-            public SimplePagedExpandPagedResponse apply(SimplePagedExpandPage input) {
-              return new SimplePagedExpandPagedResponse(input);
-            }
-          },
+          input -> new SimplePagedExpandPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClientTest.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClientTest.golden
index ba815b973f..1372cdd94e 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClientTest.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoClientTest.golden
@@ -42,8 +42,8 @@ import org.junit.Test;
 public class EchoClientTest {
   private static MockEcho mockEcho;
   private static MockServiceHelper mockServiceHelper;
-  private EchoClient client;
   private LocalChannelProvider channelProvider;
+  private EchoClient client;
 
   @BeforeClass
   public static void startStaticServer() {
@@ -838,4 +838,56 @@ public class EchoClientTest {
       // Expected exception.
     }
   }
+
+  @Test
+  public void collideNameTest() throws Exception {
+    Object expectedResponse = Object.newBuilder().setContent("content951530617").build();
+    mockEcho.addResponse(expectedResponse);
+
+    EchoRequest request =
+        EchoRequest.newBuilder()
+            .setName(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+            .setParent(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+            .setSeverity(Severity.forNumber(0))
+            .setFoobar(Foobar.newBuilder().build())
+            .build();
+
+    Object actualResponse = client.collideName(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockEcho.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    EchoRequest actualRequest = ((EchoRequest) actualRequests.get(0));
+
+    Assert.assertEquals(request.getName(), actualRequest.getName());
+    Assert.assertEquals(request.getParent(), actualRequest.getParent());
+    Assert.assertEquals(request.getContent(), actualRequest.getContent());
+    Assert.assertEquals(request.getError(), actualRequest.getError());
+    Assert.assertEquals(request.getSeverity(), actualRequest.getSeverity());
+    Assert.assertEquals(request.getFoobar(), actualRequest.getFoobar());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void collideNameExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockEcho.addException(exception);
+
+    try {
+      EchoRequest request =
+          EchoRequest.newBuilder()
+              .setName(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+              .setParent(FoobarName.ofProjectFoobarName("[PROJECT]", "[FOOBAR]").toString())
+              .setSeverity(Severity.forNumber(0))
+              .setFoobar(Foobar.newBuilder().build())
+              .build();
+      client.collideName(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoSettings.golden
index d94e7838ef..e88ba04676 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoSettings.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoSettings.golden
@@ -111,6 +111,11 @@ public class EchoSettings extends ClientSettings<EchoSettings> {
     return ((EchoStubSettings) getStubSettings()).blockSettings();
   }
 
+  /** Returns the object with the settings used for calls to collideName. */
+  public UnaryCallSettings<EchoRequest, Object> collideNameSettings() {
+    return ((EchoStubSettings) getStubSettings()).collideNameSettings();
+  }
+
   public static final EchoSettings create(EchoStubSettings stub) throws IOException {
     return new EchoSettings.Builder(stub.toBuilder()).build();
   }
@@ -195,14 +200,13 @@ public class EchoSettings extends ClientSettings<EchoSettings> {
       return ((EchoStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
@@ -263,6 +267,11 @@ public class EchoSettings extends ClientSettings<EchoSettings> {
       return getStubSettingsBuilder().blockSettings();
     }
 
+    /** Returns the builder for the settings used for calls to collideName. */
+    public UnaryCallSettings.Builder<EchoRequest, Object> collideNameSettings() {
+      return getStubSettingsBuilder().collideNameSettings();
+    }
+
     @Override
     public EchoSettings build() throws IOException {
       return new EchoSettings(this);
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/EchoStub.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStub.golden
similarity index 94%
rename from src/test/java/com/google/api/generator/gapic/composer/common/goldens/EchoStub.golden
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStub.golden
index 629e9939bb..9270f22851 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/EchoStub.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStub.golden
@@ -17,6 +17,7 @@ import com.google.showcase.v1beta1.BlockResponse;
 import com.google.showcase.v1beta1.EchoRequest;
 import com.google.showcase.v1beta1.EchoResponse;
 import com.google.showcase.v1beta1.ExpandRequest;
+import com.google.showcase.v1beta1.Object;
 import com.google.showcase.v1beta1.PagedExpandRequest;
 import com.google.showcase.v1beta1.PagedExpandResponse;
 import com.google.showcase.v1beta1.WaitMetadata;
@@ -87,6 +88,10 @@ public abstract class EchoStub implements BackgroundResource {
     throw new UnsupportedOperationException("Not implemented: blockCallable()");
   }
 
+  public UnaryCallable<EchoRequest, Object> collideNameCallable() {
+    throw new UnsupportedOperationException("Not implemented: collideNameCallable()");
+  }
+
   @Override
   public abstract void close();
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStubSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStubSettings.golden
index df88bb4b31..2006b2a30d 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStubSettings.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/EchoStubSettings.golden
@@ -41,6 +41,7 @@ import com.google.showcase.v1beta1.BlockResponse;
 import com.google.showcase.v1beta1.EchoRequest;
 import com.google.showcase.v1beta1.EchoResponse;
 import com.google.showcase.v1beta1.ExpandRequest;
+import com.google.showcase.v1beta1.Object;
 import com.google.showcase.v1beta1.PagedExpandRequest;
 import com.google.showcase.v1beta1.PagedExpandResponse;
 import com.google.showcase.v1beta1.WaitMetadata;
@@ -103,6 +104,7 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
   private final OperationCallSettings<WaitRequest, WaitResponse, WaitMetadata>
       waitOperationSettings;
   private final UnaryCallSettings<BlockRequest, BlockResponse> blockSettings;
+  private final UnaryCallSettings<EchoRequest, Object> collideNameSettings;
 
   private static final PagedListDescriptor<PagedExpandRequest, PagedExpandResponse, EchoResponse>
       PAGED_EXPAND_PAGE_STR_DESC =
@@ -262,6 +264,11 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
     return blockSettings;
   }
 
+  /** Returns the object with the settings used for calls to collideName. */
+  public UnaryCallSettings<EchoRequest, Object> collideNameSettings() {
+    return collideNameSettings;
+  }
+
   @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
   public EchoStub createStub() throws IOException {
     if (getTransportChannelProvider()
@@ -284,6 +291,11 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
     return "localhost:7469";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "localhost:7469";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -291,7 +303,9 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -340,6 +354,7 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
     waitSettings = settingsBuilder.waitSettings().build();
     waitOperationSettings = settingsBuilder.waitOperationSettings().build();
     blockSettings = settingsBuilder.blockSettings().build();
+    collideNameSettings = settingsBuilder.collideNameSettings().build();
   }
 
   /** Builder for EchoStubSettings. */
@@ -360,6 +375,7 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
     private final OperationCallSettings.Builder<WaitRequest, WaitResponse, WaitMetadata>
         waitOperationSettings;
     private final UnaryCallSettings.Builder<BlockRequest, BlockResponse> blockSettings;
+    private final UnaryCallSettings.Builder<EchoRequest, Object> collideNameSettings;
     private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
         RETRYABLE_CODE_DEFINITIONS;
 
@@ -420,6 +436,7 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       waitSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
       waitOperationSettings = OperationCallSettings.newBuilder();
       blockSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      collideNameSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
 
       unaryMethodSettingsBuilders =
           ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
@@ -427,7 +444,8 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
               pagedExpandSettings,
               simplePagedExpandSettings,
               waitSettings,
-              blockSettings);
+              blockSettings,
+              collideNameSettings);
       initDefaults(this);
     }
 
@@ -444,6 +462,7 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       waitSettings = settings.waitSettings.toBuilder();
       waitOperationSettings = settings.waitOperationSettings.toBuilder();
       blockSettings = settings.blockSettings.toBuilder();
+      collideNameSettings = settings.collideNameSettings.toBuilder();
 
       unaryMethodSettingsBuilders =
           ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
@@ -451,7 +470,8 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
               pagedExpandSettings,
               simplePagedExpandSettings,
               waitSettings,
-              blockSettings);
+              blockSettings,
+              collideNameSettings);
     }
 
     private static Builder createDefault() {
@@ -461,6 +481,8 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -496,6 +518,11 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
           .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_0_codes"))
           .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_0_params"));
 
+      builder
+          .collideNameSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_0_params"));
+
       builder
           .waitOperationSettings()
           .setInitialCallSettings(
@@ -522,14 +549,13 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
@@ -595,6 +621,11 @@ public class EchoStubSettings extends StubSettings<EchoStubSettings> {
       return blockSettings;
     }
 
+    /** Returns the builder for the settings used for calls to collideName. */
+    public UnaryCallSettings.Builder<EchoRequest, Object> collideNameSettings() {
+      return collideNameSettings;
+    }
+
     @Override
     public EchoStubSettings build() throws IOException {
       return new EchoStubSettings(this);
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcDeprecatedServiceStub.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcDeprecatedServiceStub.golden
index 431b6688f5..b472790622 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcDeprecatedServiceStub.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcDeprecatedServiceStub.golden
@@ -125,7 +125,13 @@ public class GrpcDeprecatedServiceStub extends DeprecatedServiceStub {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcEchoStub.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcEchoStub.golden
index 194849ba09..940ab7d4c4 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcEchoStub.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcEchoStub.golden
@@ -21,6 +21,7 @@ import com.google.showcase.v1beta1.BlockResponse;
 import com.google.showcase.v1beta1.EchoRequest;
 import com.google.showcase.v1beta1.EchoResponse;
 import com.google.showcase.v1beta1.ExpandRequest;
+import com.google.showcase.v1beta1.Object;
 import com.google.showcase.v1beta1.PagedExpandRequest;
 import com.google.showcase.v1beta1.PagedExpandResponse;
 import com.google.showcase.v1beta1.WaitMetadata;
@@ -117,6 +118,14 @@ public class GrpcEchoStub extends EchoStub {
           .setResponseMarshaller(ProtoUtils.marshaller(BlockResponse.getDefaultInstance()))
           .build();
 
+  private static final MethodDescriptor<EchoRequest, Object> collideNameMethodDescriptor =
+      MethodDescriptor.<EchoRequest, Object>newBuilder()
+          .setType(MethodDescriptor.MethodType.UNARY)
+          .setFullMethodName("google.showcase.v1beta1.Echo/CollideName")
+          .setRequestMarshaller(ProtoUtils.marshaller(EchoRequest.getDefaultInstance()))
+          .setResponseMarshaller(ProtoUtils.marshaller(Object.getDefaultInstance()))
+          .build();
+
   private final UnaryCallable<EchoRequest, EchoResponse> echoCallable;
   private final ServerStreamingCallable<ExpandRequest, EchoResponse> expandCallable;
   private final ClientStreamingCallable<EchoRequest, EchoResponse> collectCallable;
@@ -131,6 +140,7 @@ public class GrpcEchoStub extends EchoStub {
   private final UnaryCallable<WaitRequest, Operation> waitCallable;
   private final OperationCallable<WaitRequest, WaitResponse, WaitMetadata> waitOperationCallable;
   private final UnaryCallable<BlockRequest, BlockResponse> blockCallable;
+  private final UnaryCallable<EchoRequest, Object> collideNameCallable;
 
   private final BackgroundResource backgroundResources;
   private final GrpcOperationsStub operationsStub;
@@ -206,6 +216,10 @@ public class GrpcEchoStub extends EchoStub {
         GrpcCallSettings.<BlockRequest, BlockResponse>newBuilder()
             .setMethodDescriptor(blockMethodDescriptor)
             .build();
+    GrpcCallSettings<EchoRequest, Object> collideNameTransportSettings =
+        GrpcCallSettings.<EchoRequest, Object>newBuilder()
+            .setMethodDescriptor(collideNameMethodDescriptor)
+            .build();
 
     this.echoCallable =
         callableFactory.createUnaryCallable(
@@ -247,6 +261,9 @@ public class GrpcEchoStub extends EchoStub {
     this.blockCallable =
         callableFactory.createUnaryCallable(
             blockTransportSettings, settings.blockSettings(), clientContext);
+    this.collideNameCallable =
+        callableFactory.createUnaryCallable(
+            collideNameTransportSettings, settings.collideNameSettings(), clientContext);
 
     this.backgroundResources =
         new BackgroundResourceAggregation(clientContext.getBackgroundResources());
@@ -317,9 +334,20 @@ public class GrpcEchoStub extends EchoStub {
     return blockCallable;
   }
 
+  @Override
+  public UnaryCallable<EchoRequest, Object> collideNameCallable() {
+    return collideNameCallable;
+  }
+
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcPublisherStub.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcPublisherStub.golden
index 9e221ab5a2..b0f6557279 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcPublisherStub.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcPublisherStub.golden
@@ -9,7 +9,6 @@ import com.google.api.gax.core.BackgroundResourceAggregation;
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.longrunning.stub.GrpcOperationsStub;
@@ -190,65 +189,50 @@ public class GrpcPublisherStub extends PublisherStub {
         GrpcCallSettings.<Topic, Topic>newBuilder()
             .setMethodDescriptor(createTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<Topic>() {
-                  @Override
-                  public Map<String, String> extract(Topic request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateTopicRequest, Topic> updateTopicTransportSettings =
         GrpcCallSettings.<UpdateTopicRequest, Topic>newBuilder()
             .setMethodDescriptor(updateTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateTopicRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateTopicRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic.name", String.valueOf(request.getTopic().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic.name", String.valueOf(request.getTopic().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<PublishRequest, PublishResponse> publishTransportSettings =
         GrpcCallSettings.<PublishRequest, PublishResponse>newBuilder()
             .setMethodDescriptor(publishMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<PublishRequest>() {
-                  @Override
-                  public Map<String, String> extract(PublishRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic", String.valueOf(request.getTopic()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic", String.valueOf(request.getTopic()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetTopicRequest, Topic> getTopicTransportSettings =
         GrpcCallSettings.<GetTopicRequest, Topic>newBuilder()
             .setMethodDescriptor(getTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetTopicRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetTopicRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic", String.valueOf(request.getTopic()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic", String.valueOf(request.getTopic()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListTopicsRequest, ListTopicsResponse> listTopicsTransportSettings =
         GrpcCallSettings.<ListTopicsRequest, ListTopicsResponse>newBuilder()
             .setMethodDescriptor(listTopicsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListTopicsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListTopicsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("project", String.valueOf(request.getProject()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("project", String.valueOf(request.getProject()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListTopicSubscriptionsRequest, ListTopicSubscriptionsResponse>
@@ -257,13 +241,10 @@ public class GrpcPublisherStub extends PublisherStub {
                 .<ListTopicSubscriptionsRequest, ListTopicSubscriptionsResponse>newBuilder()
                 .setMethodDescriptor(listTopicSubscriptionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListTopicSubscriptionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListTopicSubscriptionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("topic", String.valueOf(request.getTopic()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("topic", String.valueOf(request.getTopic()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ListTopicSnapshotsRequest, ListTopicSnapshotsResponse>
@@ -271,26 +252,20 @@ public class GrpcPublisherStub extends PublisherStub {
             GrpcCallSettings.<ListTopicSnapshotsRequest, ListTopicSnapshotsResponse>newBuilder()
                 .setMethodDescriptor(listTopicSnapshotsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListTopicSnapshotsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListTopicSnapshotsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("topic", String.valueOf(request.getTopic()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("topic", String.valueOf(request.getTopic()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<DeleteTopicRequest, Empty> deleteTopicTransportSettings =
         GrpcCallSettings.<DeleteTopicRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteTopicRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteTopicRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic", String.valueOf(request.getTopic()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic", String.valueOf(request.getTopic()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DetachSubscriptionRequest, DetachSubscriptionResponse>
@@ -298,13 +273,10 @@ public class GrpcPublisherStub extends PublisherStub {
             GrpcCallSettings.<DetachSubscriptionRequest, DetachSubscriptionResponse>newBuilder()
                 .setMethodDescriptor(detachSubscriptionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<DetachSubscriptionRequest>() {
-                      @Override
-                      public Map<String, String> extract(DetachSubscriptionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("subscription", String.valueOf(request.getSubscription()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("subscription", String.valueOf(request.getSubscription()));
+                      return params.build();
                     })
                 .build();
 
@@ -430,7 +402,13 @@ public class GrpcPublisherStub extends PublisherStub {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcTestingStub.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcTestingStub.golden
index ed6f22313a..7312b79d37 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcTestingStub.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/GrpcTestingStub.golden
@@ -9,7 +9,6 @@ import com.google.api.gax.core.BackgroundResourceAggregation;
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.longrunning.stub.GrpcOperationsStub;
@@ -186,13 +185,10 @@ public class GrpcTestingStub extends TestingStub {
         GrpcCallSettings.<GetSessionRequest, Session>newBuilder()
             .setMethodDescriptor(getSessionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetSessionRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetSessionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListSessionsRequest, ListSessionsResponse> listSessionsTransportSettings =
@@ -203,83 +199,65 @@ public class GrpcTestingStub extends TestingStub {
         GrpcCallSettings.<DeleteSessionRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteSessionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteSessionRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteSessionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ReportSessionRequest, ReportSessionResponse> reportSessionTransportSettings =
         GrpcCallSettings.<ReportSessionRequest, ReportSessionResponse>newBuilder()
             .setMethodDescriptor(reportSessionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ReportSessionRequest>() {
-                  @Override
-                  public Map<String, String> extract(ReportSessionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetTestRequest, Test> getTestTransportSettings =
         GrpcCallSettings.<GetTestRequest, Test>newBuilder()
             .setMethodDescriptor(getTestMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetTestRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetTestRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListTestsRequest, ListTestsResponse> listTestsTransportSettings =
         GrpcCallSettings.<ListTestsRequest, ListTestsResponse>newBuilder()
             .setMethodDescriptor(listTestsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListTestsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListTestsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteTestRequest, Empty> deleteTestTransportSettings =
         GrpcCallSettings.<DeleteTestRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteTestMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteTestRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteTestRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<VerifyTestRequest, VerifyTestResponse> verifyTestTransportSettings =
         GrpcCallSettings.<VerifyTestRequest, VerifyTestResponse>newBuilder()
             .setMethodDescriptor(verifyTestMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<VerifyTestRequest>() {
-                  @Override
-                  public Map<String, String> extract(VerifyTestRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("answer", String.valueOf(request.getAnswer()));
-                    params.put("foo", String.valueOf(request.getFoo()));
-                    params.put("name", String.valueOf(request.getName()));
-                    params.put(
-                        "test_to_verify.name", String.valueOf(request.getTestToVerify().getName()));
-                    params.put("type", String.valueOf(request.getType()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("answer", String.valueOf(request.getAnswer()));
+                  params.put("foo", String.valueOf(request.getFoo()));
+                  params.put("name", String.valueOf(request.getName()));
+                  params.put(
+                      "test_to_verify.name", String.valueOf(request.getTestToVerify().getName()));
+                  params.put("type", String.valueOf(request.getType()));
+                  return params.build();
                 })
             .build();
 
@@ -382,7 +360,13 @@ public class GrpcTestingStub extends TestingStub {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/IdentityClient.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/IdentityClient.golden
similarity index 98%
rename from src/test/java/com/google/api/generator/gapic/composer/common/goldens/IdentityClient.golden
rename to src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/IdentityClient.golden
index 2081b3bd1c..235c0055b6 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/common/goldens/IdentityClient.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/IdentityClient.golden
@@ -1,6 +1,5 @@
 package com.google.showcase.v1beta1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -644,14 +643,7 @@ public class IdentityClient implements BackgroundResource {
       ApiFuture<ListUsersPage> futurePage =
           ListUsersPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListUsersPage, ListUsersPagedResponse>() {
-            @Override
-            public ListUsersPagedResponse apply(ListUsersPage input) {
-              return new ListUsersPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListUsersPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListUsersPagedResponse(ListUsersPage page) {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingClientTest.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingClientTest.golden
index afa0414c65..ead00722f4 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingClientTest.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingClientTest.golden
@@ -45,8 +45,8 @@ import org.junit.Test;
 public class LoggingServiceV2ClientTest {
   private static MockLoggingServiceV2 mockLoggingServiceV2;
   private static MockServiceHelper mockServiceHelper;
-  private LoggingServiceV2Client client;
   private LocalChannelProvider channelProvider;
+  private LoggingServiceV2Client client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingServiceV2StubSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingServiceV2StubSettings.golden
index 4033943f64..cc308eb5de 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingServiceV2StubSettings.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/LoggingServiceV2StubSettings.golden
@@ -428,6 +428,11 @@ public class LoggingServiceV2StubSettings extends StubSettings<LoggingServiceV2S
     return "logging.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "logging.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -435,7 +440,9 @@ public class LoggingServiceV2StubSettings extends StubSettings<LoggingServiceV2S
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -610,6 +617,8 @@ public class LoggingServiceV2StubSettings extends StubSettings<LoggingServiceV2S
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -659,14 +668,13 @@ public class LoggingServiceV2StubSettings extends StubSettings<LoggingServiceV2S
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockDeprecatedServiceImpl.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockDeprecatedServiceImpl.golden
index f400f9aa20..7092d93a9e 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockDeprecatedServiceImpl.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockDeprecatedServiceImpl.golden
@@ -15,7 +15,7 @@ import javax.annotation.Generated;
 @Generated("by gapic-generator-java")
 public class MockDeprecatedServiceImpl extends DeprecatedServiceImplBase {
   private List<AbstractMessage> requests;
-  private Queue<Object> responses;
+  private Queue<java.lang.Object> responses;
 
   public MockDeprecatedServiceImpl() {
     requests = new ArrayList<>();
@@ -31,7 +31,7 @@ public class MockDeprecatedServiceImpl extends DeprecatedServiceImplBase {
   }
 
   public void setResponses(List<AbstractMessage> responses) {
-    this.responses = new LinkedList<Object>(responses);
+    this.responses = new LinkedList<java.lang.Object>(responses);
   }
 
   public void addException(Exception exception) {
@@ -45,7 +45,7 @@ public class MockDeprecatedServiceImpl extends DeprecatedServiceImplBase {
 
   @Override
   public void fastFibonacci(FibonacciRequest request, StreamObserver<Empty> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof Empty) {
       requests.add(request);
       responseObserver.onNext(((Empty) response));
@@ -65,7 +65,7 @@ public class MockDeprecatedServiceImpl extends DeprecatedServiceImplBase {
 
   @Override
   public void slowFibonacci(FibonacciRequest request, StreamObserver<Empty> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof Empty) {
       requests.add(request);
       responseObserver.onNext(((Empty) response));
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockEchoImpl.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockEchoImpl.golden
index 50da1d568c..ae3ff13888 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockEchoImpl.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/MockEchoImpl.golden
@@ -15,7 +15,7 @@ import javax.annotation.Generated;
 @Generated("by gapic-generator-java")
 public class MockEchoImpl extends EchoImplBase {
   private List<AbstractMessage> requests;
-  private Queue<Object> responses;
+  private Queue<java.lang.Object> responses;
 
   public MockEchoImpl() {
     requests = new ArrayList<>();
@@ -31,7 +31,7 @@ public class MockEchoImpl extends EchoImplBase {
   }
 
   public void setResponses(List<AbstractMessage> responses) {
-    this.responses = new LinkedList<Object>(responses);
+    this.responses = new LinkedList<java.lang.Object>(responses);
   }
 
   public void addException(Exception exception) {
@@ -45,7 +45,7 @@ public class MockEchoImpl extends EchoImplBase {
 
   @Override
   public void echo(EchoRequest request, StreamObserver<EchoResponse> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof EchoResponse) {
       requests.add(request);
       responseObserver.onNext(((EchoResponse) response));
@@ -65,7 +65,7 @@ public class MockEchoImpl extends EchoImplBase {
 
   @Override
   public void expand(ExpandRequest request, StreamObserver<EchoResponse> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof EchoResponse) {
       requests.add(request);
       responseObserver.onNext(((EchoResponse) response));
@@ -90,7 +90,7 @@ public class MockEchoImpl extends EchoImplBase {
           @Override
           public void onNext(EchoRequest value) {
             requests.add(value);
-            final Object response = responses.remove();
+            final java.lang.Object response = responses.remove();
             if (response instanceof EchoResponse) {
               responseObserver.onNext(((EchoResponse) response));
             } else if (response instanceof Exception) {
@@ -126,7 +126,7 @@ public class MockEchoImpl extends EchoImplBase {
           @Override
           public void onNext(EchoRequest value) {
             requests.add(value);
-            final Object response = responses.remove();
+            final java.lang.Object response = responses.remove();
             if (response instanceof EchoResponse) {
               responseObserver.onNext(((EchoResponse) response));
             } else if (response instanceof Exception) {
@@ -163,7 +163,7 @@ public class MockEchoImpl extends EchoImplBase {
           @Override
           public void onNext(EchoRequest value) {
             requests.add(value);
-            final Object response = responses.remove();
+            final java.lang.Object response = responses.remove();
             if (response instanceof EchoResponse) {
               responseObserver.onNext(((EchoResponse) response));
             } else if (response instanceof Exception) {
@@ -195,7 +195,7 @@ public class MockEchoImpl extends EchoImplBase {
   @Override
   public void pagedExpand(
       PagedExpandRequest request, StreamObserver<PagedExpandResponse> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof PagedExpandResponse) {
       requests.add(request);
       responseObserver.onNext(((PagedExpandResponse) response));
@@ -216,7 +216,7 @@ public class MockEchoImpl extends EchoImplBase {
   @Override
   public void simplePagedExpand(
       PagedExpandRequest request, StreamObserver<PagedExpandResponse> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof PagedExpandResponse) {
       requests.add(request);
       responseObserver.onNext(((PagedExpandResponse) response));
@@ -236,7 +236,7 @@ public class MockEchoImpl extends EchoImplBase {
 
   @Override
   public void wait(WaitRequest request, StreamObserver<Operation> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof Operation) {
       requests.add(request);
       responseObserver.onNext(((Operation) response));
@@ -256,7 +256,7 @@ public class MockEchoImpl extends EchoImplBase {
 
   @Override
   public void block(BlockRequest request, StreamObserver<BlockResponse> responseObserver) {
-    Object response = responses.poll();
+    java.lang.Object response = responses.poll();
     if (response instanceof BlockResponse) {
       requests.add(request);
       responseObserver.onNext(((BlockResponse) response));
@@ -273,4 +273,24 @@ public class MockEchoImpl extends EchoImplBase {
                   Exception.class.getName())));
     }
   }
+
+  @Override
+  public void collideName(EchoRequest request, StreamObserver<Object> responseObserver) {
+    java.lang.Object response = responses.poll();
+    if (response instanceof Object) {
+      requests.add(request);
+      responseObserver.onNext(((Object) response));
+      responseObserver.onCompleted();
+    } else if (response instanceof Exception) {
+      responseObserver.onError(((Exception) response));
+    } else {
+      responseObserver.onError(
+          new IllegalArgumentException(
+              String.format(
+                  "Unrecognized response type %s for method CollideName, expected %s or %s",
+                  response == null ? "null" : response.getClass().getName(),
+                  Object.class.getName(),
+                  Exception.class.getName())));
+    }
+  }
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/PublisherStubSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/PublisherStubSettings.golden
index 41585255b2..d050f8a921 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/PublisherStubSettings.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/PublisherStubSettings.golden
@@ -437,6 +437,11 @@ public class PublisherStubSettings extends StubSettings<PublisherStubSettings> {
     return "pubsub.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "pubsub.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -444,7 +449,9 @@ public class PublisherStubSettings extends StubSettings<PublisherStubSettings> {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -651,6 +658,8 @@ public class PublisherStubSettings extends StubSettings<PublisherStubSettings> {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -717,14 +726,13 @@ public class PublisherStubSettings extends StubSettings<PublisherStubSettings> {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/SubscriberClientTest.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/SubscriberClientTest.golden
index 941e4d1ea6..62467289ae 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/SubscriberClientTest.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/SubscriberClientTest.golden
@@ -36,10 +36,10 @@ import org.junit.Test;
 
 @Generated("by gapic-generator-java")
 public class SubscriberClientTest {
-  private static MockSubscriber mockSubscriber;
   private static MockServiceHelper mockServiceHelper;
-  private SubscriberClient client;
+  private static MockSubscriber mockSubscriber;
   private LocalChannelProvider channelProvider;
+  private SubscriberClient client;
 
   @BeforeClass
   public static void startStaticServer() {
@@ -778,6 +778,84 @@ public class SubscriberClientTest {
         PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
     mockSubscriber.addResponse(expectedResponse);
 
+    SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
+    int maxMessages = 496131527;
+
+    PullResponse actualResponse = client.pull(subscription, maxMessages);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockSubscriber.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    PullRequest actualRequest = ((PullRequest) actualRequests.get(0));
+
+    Assert.assertEquals(subscription.toString(), actualRequest.getSubscription());
+    Assert.assertEquals(maxMessages, actualRequest.getMaxMessages());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void pullExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockSubscriber.addException(exception);
+
+    try {
+      SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
+      int maxMessages = 496131527;
+      client.pull(subscription, maxMessages);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void pullTest2() throws Exception {
+    PullResponse expectedResponse =
+        PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
+    mockSubscriber.addResponse(expectedResponse);
+
+    String subscription = "subscription341203229";
+    int maxMessages = 496131527;
+
+    PullResponse actualResponse = client.pull(subscription, maxMessages);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockSubscriber.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    PullRequest actualRequest = ((PullRequest) actualRequests.get(0));
+
+    Assert.assertEquals(subscription, actualRequest.getSubscription());
+    Assert.assertEquals(maxMessages, actualRequest.getMaxMessages());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void pullExceptionTest2() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockSubscriber.addException(exception);
+
+    try {
+      String subscription = "subscription341203229";
+      int maxMessages = 496131527;
+      client.pull(subscription, maxMessages);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void pullTest3() throws Exception {
+    PullResponse expectedResponse =
+        PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
+    mockSubscriber.addResponse(expectedResponse);
+
     SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
     boolean returnImmediately = true;
     int maxMessages = 496131527;
@@ -799,7 +877,7 @@ public class SubscriberClientTest {
   }
 
   @Test
-  public void pullExceptionTest() throws Exception {
+  public void pullExceptionTest3() throws Exception {
     StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
     mockSubscriber.addException(exception);
 
@@ -815,7 +893,7 @@ public class SubscriberClientTest {
   }
 
   @Test
-  public void pullTest2() throws Exception {
+  public void pullTest4() throws Exception {
     PullResponse expectedResponse =
         PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
     mockSubscriber.addResponse(expectedResponse);
@@ -841,7 +919,7 @@ public class SubscriberClientTest {
   }
 
   @Test
-  public void pullExceptionTest2() throws Exception {
+  public void pullExceptionTest4() throws Exception {
     StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
     mockSubscriber.addException(exception);
 
@@ -861,6 +939,8 @@ public class SubscriberClientTest {
     StreamingPullResponse expectedResponse =
         StreamingPullResponse.newBuilder()
             .addAllReceivedMessages(new ArrayList<ReceivedMessage>())
+            .setSubscriptionProperties(
+                StreamingPullResponse.SubscriptionProperties.newBuilder().build())
             .build();
     mockSubscriber.addResponse(expectedResponse);
     StreamingPullRequest request =
diff --git a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/TestingClientTest.golden b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/TestingClientTest.golden
index d124cfb5e2..76a18a39b5 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/TestingClientTest.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/grpc/goldens/TestingClientTest.golden
@@ -31,10 +31,10 @@ import org.junit.Test;
 
 @Generated("by gapic-generator-java")
 public class TestingClientTest {
-  private static MockTesting mockTesting;
   private static MockServiceHelper mockServiceHelper;
-  private TestingClient client;
+  private static MockTesting mockTesting;
   private LocalChannelProvider channelProvider;
+  private TestingClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/composer/resourcename/BUILD.bazel
index a62cd2dad8..c62de44173 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/BUILD.bazel
@@ -23,6 +23,7 @@ TEST_DEPS = [
     "//src/main/java/com/google/api/generator/gapic/composer/resourcename",
     "//src/main/java/com/google/api/generator/gapic/model",
     "//src/main/java/com/google/api/generator/gapic/protoparser",
+    "//src/test/java/com/google/api/generator/gapic/composer/common",
     "//src/test/java/com/google/api/generator/gapic/testdata:showcase_java_proto",
     "//src/test/java/com/google/api/generator/test/framework:asserts",
     "//src/test/java/com/google/api/generator/test/framework:utils",
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposerTest.java
index 16251dc124..c54218a52e 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposerTest.java
@@ -15,13 +15,14 @@
 package com.google.api.generator.gapic.composer.resourcename;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.composer.common.TestProtoLoader;
 import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.ResourceName;
-import com.google.api.generator.gapic.model.Service;
 import com.google.api.generator.gapic.protoparser.Parser;
 import com.google.api.generator.test.framework.Assert;
 import com.google.api.generator.test.framework.Utils;
@@ -94,14 +95,15 @@ public void generateResourceNameClass_echoFoobarMultiplePatterns() {
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
-    List<Service> services =
-        Parser.parseService(
-            echoFileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
+    Parser.parseService(
+        echoFileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
 
     ResourceName foobarResname = resourceNames.get("showcase.googleapis.com/Foobar");
     assertThat(outputResourceNames).contains(foobarResname);
 
-    GapicClass clazz = ResourceNameHelperClassComposer.instance().generate(foobarResname);
+    GapicClass clazz =
+        ResourceNameHelperClassComposer.instance()
+            .generate(foobarResname, TestProtoLoader.instance().parseShowcaseEcho());
 
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
@@ -136,20 +138,16 @@ public void generateResourceNameClass_loggingOnePatternMultipleVariables() {
     resourceNames.putAll(Parser.parseResourceNames(commonResourcesFileDescriptor));
 
     Set<ResourceName> outputResourceNames = new HashSet<>();
-    List<Service> services =
-        Parser.parseService(
-            serviceFileDescriptor,
-            messageTypes,
-            resourceNames,
-            Optional.empty(),
-            outputResourceNames);
+    Parser.parseService(
+        serviceFileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
 
     ResourceName billingAccountLocationResname =
         resourceNames.get("logging.googleapis.com/BillingAccountLocation");
     assertThat(outputResourceNames).contains(billingAccountLocationResname);
 
     GapicClass clazz =
-        ResourceNameHelperClassComposer.instance().generate(billingAccountLocationResname);
+        ResourceNameHelperClassComposer.instance()
+            .generate(billingAccountLocationResname, TestProtoLoader.instance().parseLogging());
 
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
@@ -168,18 +166,15 @@ public void generateResourceNameClass_testingSessionOnePattern() {
     Map<String, Message> messageTypes = Parser.parseMessages(testingFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(testingFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
-    List<Service> services =
-        Parser.parseService(
-            testingFileDescriptor,
-            messageTypes,
-            resourceNames,
-            Optional.empty(),
-            outputResourceNames);
+    Parser.parseService(
+        testingFileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
 
     ResourceName sessionResname = resourceNames.get("showcase.googleapis.com/Session");
     assertThat(outputResourceNames).contains(sessionResname);
 
-    GapicClass clazz = ResourceNameHelperClassComposer.instance().generate(sessionResname);
+    GapicClass clazz =
+        ResourceNameHelperClassComposer.instance()
+            .generate(sessionResname, TestProtoLoader.instance().parseShowcaseTesting());
 
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
@@ -197,18 +192,15 @@ public void generateResourceNameClass_testingBlueprintPatternWithNonSlashSeparat
     Map<String, Message> messageTypes = Parser.parseMessages(testingFileDescriptor);
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(testingFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
-    List<Service> services =
-        Parser.parseService(
-            testingFileDescriptor,
-            messageTypes,
-            resourceNames,
-            Optional.empty(),
-            outputResourceNames);
+    Parser.parseService(
+        testingFileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
 
     ResourceName testResname = resourceNames.get("showcase.googleapis.com/Test");
     assertThat(outputResourceNames).contains(testResname);
 
-    GapicClass clazz = ResourceNameHelperClassComposer.instance().generate(testResname);
+    GapicClass clazz =
+        ResourceNameHelperClassComposer.instance()
+            .generate(testResname, TestProtoLoader.instance().parseShowcaseTesting());
 
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
@@ -231,7 +223,9 @@ public void generateResourceNameClass_childSingleton() {
             .setDescription("This is a description")
             .build();
 
-    GapicClass clazz = ResourceNameHelperClassComposer.instance().generate(agentResname);
+    GapicContext irrelevantContext = TestProtoLoader.instance().parseShowcaseEcho();
+    GapicClass clazz =
+        ResourceNameHelperClassComposer.instance().generate(agentResname, irrelevantContext);
     JavaWriterVisitor visitor = new JavaWriterVisitor();
     clazz.classDefinition().accept(visitor);
     Utils.saveCodegenToFile(this.getClass(), "AgentName.golden", visitor.write());
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameTokenizerTest.java b/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameTokenizerTest.java
index 6e17170841..b49e731db2 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameTokenizerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameTokenizerTest.java
@@ -15,9 +15,8 @@
 package com.google.api.generator.gapic.composer.resourcename;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
-import com.google.api.generator.gapic.composer.resourcename.ResourceNameTokenizer;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.showcase.v1beta1.EchoOuterClass;
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/AgentName.golden b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/AgentName.golden
index 595151d8c1..76f96eead8 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/AgentName.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/AgentName.golden
@@ -164,7 +164,7 @@ public class AgentName implements ResourceName {
   }
 
   @Override
-  public boolean equals(Object o) {
+  public boolean equals(java.lang.Object o) {
     if (o == this) {
       return true;
     }
@@ -217,8 +217,8 @@ public class AgentName implements ResourceName {
       Preconditions.checkArgument(
           Objects.equals(agentName.pathTemplate, PROJECT_LOCATION),
           "toBuilder is only supported when AgentName has the pattern of projects/{project}/locations/{location}/agent");
-      project = agentName.project;
-      location = agentName.location;
+      this.project = agentName.project;
+      this.location = agentName.location;
     }
 
     public AgentName build() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/BillingAccountLocationName.golden b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/BillingAccountLocationName.golden
index ba8efd9eb6..68c8b4c472 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/BillingAccountLocationName.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/BillingAccountLocationName.golden
@@ -120,7 +120,7 @@ public class BillingAccountLocationName implements ResourceName {
   }
 
   @Override
-  public boolean equals(Object o) {
+  public boolean equals(java.lang.Object o) {
     if (o == this) {
       return true;
     }
@@ -168,8 +168,8 @@ public class BillingAccountLocationName implements ResourceName {
     }
 
     private Builder(BillingAccountLocationName billingAccountLocationName) {
-      billingAccount = billingAccountLocationName.billingAccount;
-      location = billingAccountLocationName.location;
+      this.billingAccount = billingAccountLocationName.billingAccount;
+      this.location = billingAccountLocationName.location;
     }
 
     public BillingAccountLocationName build() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/FoobarName.golden b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/FoobarName.golden
index f9b1fe01e3..4af08e31b7 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/FoobarName.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/FoobarName.golden
@@ -258,7 +258,7 @@ public class FoobarName implements ResourceName {
   }
 
   @Override
-  public boolean equals(Object o) {
+  public boolean equals(java.lang.Object o) {
     if (o == this) {
       return true;
     }
@@ -317,8 +317,8 @@ public class FoobarName implements ResourceName {
       Preconditions.checkArgument(
           Objects.equals(foobarName.pathTemplate, PROJECT_FOOBAR),
           "toBuilder is only supported when FoobarName has the pattern of projects/{project}/foobars/{foobar}");
-      project = foobarName.project;
-      foobar = foobarName.foobar;
+      this.project = foobarName.project;
+      this.foobar = foobarName.foobar;
     }
 
     public FoobarName build() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/SessionName.golden b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/SessionName.golden
index 82ed52244b..d61bb14c47 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/SessionName.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/SessionName.golden
@@ -142,7 +142,7 @@ public class SessionName implements ResourceName {
     }
 
     private Builder(SessionName sessionName) {
-      session = sessionName.session;
+      this.session = sessionName.session;
     }
 
     public SessionName build() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/TestName.golden b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/TestName.golden
index 5f99dac9ee..1864a4e7f9 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/TestName.golden
+++ b/src/test/java/com/google/api/generator/gapic/composer/resourcename/goldens/TestName.golden
@@ -194,9 +194,9 @@ public class TestName implements ResourceName {
     }
 
     private Builder(TestName testName) {
-      session = testName.session;
-      shardId = testName.shardId;
-      testId = testName.testId;
+      this.session = testName.session;
+      this.shardId = testName.shardId;
+      this.testId = testName.testId;
     }
 
     public TestName build() {
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/composer/rest/BUILD.bazel
new file mode 100644
index 0000000000..c4532b3599
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/BUILD.bazel
@@ -0,0 +1,92 @@
+load("@rules_java//java:defs.bzl", "java_proto_library", "java_test")
+load("//:rules_bazel/java/java_diff_test.bzl", "golden_update")
+
+package(default_visibility = ["//visibility:public"])
+
+TESTS = [
+    "HttpJsonServiceCallableFactoryClassComposerTest",
+    "HttpJsonServiceStubClassComposerTest",
+    "ServiceClientTestClassComposerTest",
+    "ServiceSettingsClassComposerTest",
+    "ServiceStubSettingsClassComposerTest",
+]
+
+COMMON_SRCS = [
+    "RestTestProtoLoader.java",
+]
+
+TEST_DEPS = [
+    ":common_resources_java_proto",
+    "//:service_config_java_proto",
+    "//src/main/java/com/google/api/generator/engine/ast",
+    "//src/main/java/com/google/api/generator/engine/writer",
+    "//src/main/java/com/google/api/generator/gapic/composer",
+    "//src/main/java/com/google/api/generator/gapic/composer/common",
+    "//src/main/java/com/google/api/generator/gapic/composer/rest",
+    "//src/test/java/com/google/api/generator/gapic/composer/common",
+    "//src/test/java/com/google/api/generator/test/framework:asserts",
+    "//src/test/java/com/google/api/generator/test/framework:utils",
+    "//src/main/java/com/google/api/generator/gapic/composer/samplecode",
+    "//src/test/java/com/google/api/generator/testutils",
+    "//src/main/java/com/google/api/generator/gapic/model",
+    "//src/main/java/com/google/api/generator/gapic/protoparser",
+    "//src/main/java/com/google/api/generator/gapic/composer/defaultvalue",
+    "//src/test/java/com/google/api/generator/gapic/testdata:deprecated_service_java_proto",
+    "//src/test/java/com/google/api/generator/gapic/testdata:showcase_java_proto",
+    "//src/test/java/com/google/api/generator/gapic/testdata:testgapic_java_proto",
+    "@com_google_api_api_common//jar",
+    "@com_google_api_gax_java//gax",
+    "@com_google_api_api_common",
+    "@com_google_googleapis//google/logging/v2:logging_java_proto",
+    "@com_google_googleapis//google/pubsub/v1:pubsub_java_proto",
+    "@com_google_googleapis//google/rpc:rpc_java_proto",
+    "@com_google_guava_guava",
+    "@com_google_protobuf//:protobuf_java",
+    "@com_google_truth_truth//jar",
+    "@junit_junit//jar",
+]
+
+filegroup(
+    name = "rest_files",
+    srcs = glob(["*.java"]),
+)
+
+java_proto_library(
+    name = "common_resources_java_proto",
+    deps = [
+        "@com_google_googleapis//google/cloud:common_resources_proto",
+    ],
+)
+
+[java_test(
+    name = test_name,
+    size = "medium",
+    srcs = [
+        "{0}.java".format(test_name),
+    ] + COMMON_SRCS,
+    data = [
+        "//src/test/java/com/google/api/generator/gapic/composer/rest/goldens:goldens_files",
+        "//src/test/java/com/google/api/generator/gapic/testdata:gapic_config_files",
+        "//src/test/java/com/google/api/generator/gapic/testdata:service_config_files",
+    ],
+    test_class = "com.google.api.generator.gapic.composer.rest.{0}".format(test_name),
+    deps = TEST_DEPS,
+) for test_name in TESTS]
+
+# Run `bazel run src/test/java/com/google/api/generator/gapic/composer/rest:testTargetName_update`
+# to update goldens as expected generated code.
+# `ServiceClient*` tests are not supported now since they are still in active development.
+
+[golden_update(
+    name = "{0}_update".format(test_name),
+    srcs = [
+        "{0}.java".format(test_name),
+    ] + COMMON_SRCS,
+    data = [
+        "//src/test/java/com/google/api/generator/gapic/composer/rest/goldens:goldens_files",
+        "//src/test/java/com/google/api/generator/gapic/testdata:gapic_config_files",
+        "//src/test/java/com/google/api/generator/gapic/testdata:service_config_files",
+    ],
+    test_class = "com.google.api.generator.gapic.composer.rest.{0}".format(test_name),
+    deps = TEST_DEPS,
+) for test_name in TESTS]
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposerTest.java
new file mode 100644
index 0000000000..2207e3d7d1
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceCallableFactoryClassComposerTest.java
@@ -0,0 +1,43 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.test.framework.Assert;
+import com.google.api.generator.test.framework.Utils;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+public class HttpJsonServiceCallableFactoryClassComposerTest {
+  @Test
+  public void generateServiceClasses() {
+    GapicContext context = RestTestProtoLoader.instance().parseCompliance();
+    Service echoProtoService = context.services().get(0);
+    GapicClass clazz =
+        HttpJsonServiceCallableFactoryClassComposer.instance().generate(context, echoProtoService);
+
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    Utils.saveCodegenToFile(
+        this.getClass(), "HttpJsonComplianceCallableFactory.golden", visitor.write());
+    Path goldenFilePath =
+        Paths.get(Utils.getGoldenDir(this.getClass()), "HttpJsonComplianceCallableFactory.golden");
+    Assert.assertCodeEquals(goldenFilePath, visitor.write());
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceStubClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceStubClassComposerTest.java
new file mode 100644
index 0000000000..1efb7fd67b
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/HttpJsonServiceStubClassComposerTest.java
@@ -0,0 +1,42 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.test.framework.Assert;
+import com.google.api.generator.test.framework.Utils;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+public class HttpJsonServiceStubClassComposerTest {
+  @Test
+  public void generateHttpJsonServiceStubClass_simple() {
+    GapicContext context = RestTestProtoLoader.instance().parseCompliance();
+    Service echoProtoService = context.services().get(0);
+    GapicClass clazz =
+        HttpJsonServiceStubClassComposer.instance().generate(context, echoProtoService);
+
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    Utils.saveCodegenToFile(this.getClass(), "HttpJsonComplianceStub.golden", visitor.write());
+    Path goldenFilePath =
+        Paths.get(Utils.getGoldenDir(this.getClass()), "HttpJsonComplianceStub.golden");
+    Assert.assertCodeEquals(goldenFilePath, visitor.write());
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/RestTestProtoLoader.java b/src/test/java/com/google/api/generator/gapic/composer/rest/RestTestProtoLoader.java
new file mode 100644
index 0000000000..13ef1cea69
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/RestTestProtoLoader.java
@@ -0,0 +1,78 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.google.api.generator.gapic.composer.common.TestProtoLoader;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.GapicServiceConfig;
+import com.google.api.generator.gapic.model.Message;
+import com.google.api.generator.gapic.model.ResourceName;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.model.Transport;
+import com.google.api.generator.gapic.protoparser.Parser;
+import com.google.api.generator.gapic.protoparser.ServiceConfigParser;
+import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.Descriptors.ServiceDescriptor;
+import com.google.showcase.v1beta1.ComplianceOuterClass;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+public class RestTestProtoLoader extends TestProtoLoader {
+  private static final RestTestProtoLoader INSTANCE = new RestTestProtoLoader();
+
+  protected RestTestProtoLoader() {
+    super(Transport.REST, "src/test/java/com/google/api/generator/gapic/testdata/");
+  }
+
+  public static RestTestProtoLoader instance() {
+    return INSTANCE;
+  }
+
+  public GapicContext parseCompliance() {
+    FileDescriptor echoFileDescriptor = ComplianceOuterClass.getDescriptor();
+    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
+    assertEquals(echoServiceDescriptor.getName(), "Compliance");
+
+    Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
+    Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
+    Set<ResourceName> outputResourceNames = new HashSet<>();
+    List<Service> services =
+        Parser.parseService(
+            echoFileDescriptor, messageTypes, resourceNames, Optional.empty(), outputResourceNames);
+
+    String jsonFilename = "showcase_grpc_service_config.json";
+    Path jsonPath = Paths.get(getTestFilesDirectory(), jsonFilename);
+    Optional<GapicServiceConfig> configOpt = ServiceConfigParser.parse(jsonPath.toString());
+    assertTrue(configOpt.isPresent());
+    GapicServiceConfig config = configOpt.get();
+
+    return GapicContext.builder()
+        .setMessages(messageTypes)
+        .setResourceNames(resourceNames)
+        .setServices(services)
+        .setServiceConfig(config)
+        .setHelperResourceNames(outputResourceNames)
+        .setTransport(getTransport())
+        .build();
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceClientTestClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceClientTestClassComposerTest.java
new file mode 100644
index 0000000000..028f4cca14
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceClientTestClassComposerTest.java
@@ -0,0 +1,43 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import static com.google.api.generator.test.framework.Assert.assertCodeEquals;
+
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.test.framework.Utils;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+public class ServiceClientTestClassComposerTest {
+  @Test
+  public void generateClientTest_echoClient() {
+    GapicContext context = RestTestProtoLoader.instance().parseCompliance();
+    Service echoProtoService = context.services().get(0);
+    GapicClass clazz =
+        ServiceClientTestClassComposer.instance().generate(context, echoProtoService);
+
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    Utils.saveCodegenToFile(this.getClass(), "ComplianceClientTest.golden", visitor.write());
+    Path goldenFilePath =
+        Paths.get(Utils.getGoldenDir(this.getClass()), "ComplianceClientTest.golden");
+    assertCodeEquals(goldenFilePath, visitor.write());
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceSettingsClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceSettingsClassComposerTest.java
new file mode 100644
index 0000000000..5631b00607
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceSettingsClassComposerTest.java
@@ -0,0 +1,41 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.test.framework.Assert;
+import com.google.api.generator.test.framework.Utils;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+public class ServiceSettingsClassComposerTest {
+  @Test
+  public void generateServiceClasses() {
+    GapicContext context = RestTestProtoLoader.instance().parseCompliance();
+    Service echoProtoService = context.services().get(0);
+    GapicClass clazz = ServiceSettingsClassComposer.instance().generate(context, echoProtoService);
+
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    Utils.saveCodegenToFile(this.getClass(), "ComplianceSettings.golden", visitor.write());
+    Path goldenFilePath =
+        Paths.get(Utils.getGoldenDir(this.getClass()), "ComplianceSettings.golden");
+    Assert.assertCodeEquals(goldenFilePath, visitor.write());
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceStubSettingsClassComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceStubSettingsClassComposerTest.java
new file mode 100644
index 0000000000..53392a549e
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/ServiceStubSettingsClassComposerTest.java
@@ -0,0 +1,42 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.api.generator.gapic.composer.rest;
+
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicContext;
+import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.test.framework.Assert;
+import com.google.api.generator.test.framework.Utils;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.junit.Test;
+
+public class ServiceStubSettingsClassComposerTest {
+  @Test
+  public void generateServiceStubSettingsClasses_basic() {
+    GapicContext context = RestTestProtoLoader.instance().parseCompliance();
+    Service echoProtoService = context.services().get(0);
+    GapicClass clazz =
+        ServiceStubSettingsClassComposer.instance().generate(context, echoProtoService);
+
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    Utils.saveCodegenToFile(this.getClass(), "ComplianceStubSettings.golden", visitor.write());
+    Path goldenFilePath =
+        Paths.get(Utils.getGoldenDir(this.getClass()), "ComplianceStubSettings.golden");
+    Assert.assertCodeEquals(goldenFilePath, visitor.write());
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/BUILD.bazel
new file mode 100644
index 0000000000..85ac1a519e
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/BUILD.bazel
@@ -0,0 +1,6 @@
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "goldens_files",
+    srcs = glob(["*.golden"]),
+)
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceClientTest.golden b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceClientTest.golden
new file mode 100644
index 0000000000..9bc2d799ce
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceClientTest.golden
@@ -0,0 +1,368 @@
+package com.google.showcase.v1beta1;
+
+import com.google.api.gax.core.NoCredentialsProvider;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.testing.MockHttpService;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ApiException;
+import com.google.api.gax.rpc.ApiExceptionFactory;
+import com.google.api.gax.rpc.InvalidArgumentException;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.testing.FakeStatusCode;
+import com.google.showcase.v1beta1.stub.HttpJsonComplianceStub;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+@Generated("by gapic-generator-java")
+public class ComplianceClientTest {
+  private static MockHttpService mockService;
+  private static ComplianceClient client;
+
+  @BeforeClass
+  public static void startStaticServer() throws IOException {
+    mockService =
+        new MockHttpService(
+            HttpJsonComplianceStub.getMethodDescriptors(), ComplianceSettings.getDefaultEndpoint());
+    ComplianceSettings settings =
+        ComplianceSettings.newBuilder()
+            .setTransportChannelProvider(
+                ComplianceSettings.defaultHttpJsonTransportProviderBuilder()
+                    .setHttpTransport(mockService)
+                    .build())
+            .setCredentialsProvider(NoCredentialsProvider.create())
+            .build();
+    client = ComplianceClient.create(settings);
+  }
+
+  @AfterClass
+  public static void stopServer() {
+    client.close();
+  }
+
+  @Before
+  public void setUp() {}
+
+  @After
+  public void tearDown() throws Exception {
+    mockService.reset();
+  }
+
+  @Test
+  public void repeatDataBodyTest() throws Exception {
+    RepeatResponse expectedResponse =
+        RepeatResponse.newBuilder().setInfo(ComplianceData.newBuilder().build()).build();
+    mockService.addResponse(expectedResponse);
+
+    RepeatRequest request =
+        RepeatRequest.newBuilder()
+            .setName("name3373707")
+            .setInfo(ComplianceData.newBuilder().build())
+            .setServerVerify(true)
+            .build();
+
+    RepeatResponse actualResponse = client.repeatDataBody(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void repeatDataBodyExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      RepeatRequest request =
+          RepeatRequest.newBuilder()
+              .setName("name3373707")
+              .setInfo(ComplianceData.newBuilder().build())
+              .setServerVerify(true)
+              .build();
+      client.repeatDataBody(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void repeatDataBodyInfoTest() throws Exception {
+    RepeatResponse expectedResponse =
+        RepeatResponse.newBuilder().setInfo(ComplianceData.newBuilder().build()).build();
+    mockService.addResponse(expectedResponse);
+
+    RepeatRequest request =
+        RepeatRequest.newBuilder()
+            .setName("name3373707")
+            .setInfo(ComplianceData.newBuilder().build())
+            .setServerVerify(true)
+            .build();
+
+    RepeatResponse actualResponse = client.repeatDataBodyInfo(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void repeatDataBodyInfoExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      RepeatRequest request =
+          RepeatRequest.newBuilder()
+              .setName("name3373707")
+              .setInfo(ComplianceData.newBuilder().build())
+              .setServerVerify(true)
+              .build();
+      client.repeatDataBodyInfo(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void repeatDataQueryTest() throws Exception {
+    RepeatResponse expectedResponse =
+        RepeatResponse.newBuilder().setInfo(ComplianceData.newBuilder().build()).build();
+    mockService.addResponse(expectedResponse);
+
+    RepeatRequest request =
+        RepeatRequest.newBuilder()
+            .setName("name3373707")
+            .setInfo(ComplianceData.newBuilder().build())
+            .setServerVerify(true)
+            .build();
+
+    RepeatResponse actualResponse = client.repeatDataQuery(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void repeatDataQueryExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      RepeatRequest request =
+          RepeatRequest.newBuilder()
+              .setName("name3373707")
+              .setInfo(ComplianceData.newBuilder().build())
+              .setServerVerify(true)
+              .build();
+      client.repeatDataQuery(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void repeatDataSimplePathTest() throws Exception {
+    RepeatResponse expectedResponse =
+        RepeatResponse.newBuilder().setInfo(ComplianceData.newBuilder().build()).build();
+    mockService.addResponse(expectedResponse);
+
+    RepeatRequest request =
+        RepeatRequest.newBuilder()
+            .setName("name3373707")
+            .setInfo(ComplianceData.newBuilder().build())
+            .setServerVerify(true)
+            .build();
+
+    RepeatResponse actualResponse = client.repeatDataSimplePath(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void repeatDataSimplePathExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      RepeatRequest request =
+          RepeatRequest.newBuilder()
+              .setName("name3373707")
+              .setInfo(ComplianceData.newBuilder().build())
+              .setServerVerify(true)
+              .build();
+      client.repeatDataSimplePath(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void repeatDataPathResourceTest() throws Exception {
+    RepeatResponse expectedResponse =
+        RepeatResponse.newBuilder().setInfo(ComplianceData.newBuilder().build()).build();
+    mockService.addResponse(expectedResponse);
+
+    RepeatRequest request =
+        RepeatRequest.newBuilder()
+            .setName("name3373707")
+            .setInfo(ComplianceData.newBuilder().build())
+            .setServerVerify(true)
+            .build();
+
+    RepeatResponse actualResponse = client.repeatDataPathResource(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void repeatDataPathResourceExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      RepeatRequest request =
+          RepeatRequest.newBuilder()
+              .setName("name3373707")
+              .setInfo(ComplianceData.newBuilder().build())
+              .setServerVerify(true)
+              .build();
+      client.repeatDataPathResource(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void repeatDataPathTrailingResourceTest() throws Exception {
+    RepeatResponse expectedResponse =
+        RepeatResponse.newBuilder().setInfo(ComplianceData.newBuilder().build()).build();
+    mockService.addResponse(expectedResponse);
+
+    RepeatRequest request =
+        RepeatRequest.newBuilder()
+            .setName("name3373707")
+            .setInfo(ComplianceData.newBuilder().build())
+            .setServerVerify(true)
+            .build();
+
+    RepeatResponse actualResponse = client.repeatDataPathTrailingResource(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void repeatDataPathTrailingResourceExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      RepeatRequest request =
+          RepeatRequest.newBuilder()
+              .setName("name3373707")
+              .setInfo(ComplianceData.newBuilder().build())
+              .setServerVerify(true)
+              .build();
+      client.repeatDataPathTrailingResource(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceSettings.golden
new file mode 100644
index 0000000000..11af8d46ae
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceSettings.golden
@@ -0,0 +1,218 @@
+package com.google.showcase.v1beta1;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientSettings;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.showcase.v1beta1.stub.ComplianceStubSettings;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link ComplianceClient}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (localhost) and default port (7469) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of repeatDataBody to 30 seconds:
+ *
+ * <pre>{@code
+ * ComplianceSettings.Builder complianceSettingsBuilder = ComplianceSettings.newBuilder();
+ * complianceSettingsBuilder
+ *     .repeatDataBodySettings()
+ *     .setRetrySettings(
+ *         complianceSettingsBuilder
+ *             .repeatDataBodySettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * ComplianceSettings complianceSettings = complianceSettingsBuilder.build();
+ * }</pre>
+ */
+@BetaApi
+@Generated("by gapic-generator-java")
+public class ComplianceSettings extends ClientSettings<ComplianceSettings> {
+
+  /** Returns the object with the settings used for calls to repeatDataBody. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataBodySettings() {
+    return ((ComplianceStubSettings) getStubSettings()).repeatDataBodySettings();
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataBodyInfo. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataBodyInfoSettings() {
+    return ((ComplianceStubSettings) getStubSettings()).repeatDataBodyInfoSettings();
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataQuery. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataQuerySettings() {
+    return ((ComplianceStubSettings) getStubSettings()).repeatDataQuerySettings();
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataSimplePath. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataSimplePathSettings() {
+    return ((ComplianceStubSettings) getStubSettings()).repeatDataSimplePathSettings();
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataPathResource. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataPathResourceSettings() {
+    return ((ComplianceStubSettings) getStubSettings()).repeatDataPathResourceSettings();
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataPathTrailingResource. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataPathTrailingResourceSettings() {
+    return ((ComplianceStubSettings) getStubSettings()).repeatDataPathTrailingResourceSettings();
+  }
+
+  public static final ComplianceSettings create(ComplianceStubSettings stub) throws IOException {
+    return new ComplianceSettings.Builder(stub.toBuilder()).build();
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return ComplianceStubSettings.defaultExecutorProviderBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return ComplianceStubSettings.getDefaultEndpoint();
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return ComplianceStubSettings.getDefaultServiceScopes();
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return ComplianceStubSettings.defaultCredentialsProviderBuilder();
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return ComplianceStubSettings.defaultHttpJsonTransportProviderBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return ComplianceStubSettings.defaultTransportChannelProvider();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return ComplianceStubSettings.defaultApiClientHeaderProviderBuilder();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected ComplianceSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+  }
+
+  /** Builder for ComplianceSettings. */
+  public static class Builder extends ClientSettings.Builder<ComplianceSettings, Builder> {
+
+    protected Builder() throws IOException {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(ComplianceStubSettings.newBuilder(clientContext));
+    }
+
+    protected Builder(ComplianceSettings settings) {
+      super(settings.getStubSettings().toBuilder());
+    }
+
+    protected Builder(ComplianceStubSettings.Builder stubSettings) {
+      super(stubSettings);
+    }
+
+    private static Builder createDefault() {
+      return new Builder(ComplianceStubSettings.newBuilder());
+    }
+
+    public ComplianceStubSettings.Builder getStubSettingsBuilder() {
+      return ((ComplianceStubSettings.Builder) getStubSettings());
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(
+          getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
+      return this;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataBody. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataBodySettings() {
+      return getStubSettingsBuilder().repeatDataBodySettings();
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataBodyInfo. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataBodyInfoSettings() {
+      return getStubSettingsBuilder().repeatDataBodyInfoSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataQuery. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataQuerySettings() {
+      return getStubSettingsBuilder().repeatDataQuerySettings();
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataSimplePath. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataSimplePathSettings() {
+      return getStubSettingsBuilder().repeatDataSimplePathSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataPathResource. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataPathResourceSettings() {
+      return getStubSettingsBuilder().repeatDataPathResourceSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataPathTrailingResource. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataPathTrailingResourceSettings() {
+      return getStubSettingsBuilder().repeatDataPathTrailingResourceSettings();
+    }
+
+    @Override
+    public ComplianceSettings build() throws IOException {
+      return new ComplianceSettings(this);
+    }
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceStubSettings.golden b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceStubSettings.golden
new file mode 100644
index 0000000000..a858c0123e
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/ComplianceStubSettings.golden
@@ -0,0 +1,366 @@
+package com.google.showcase.v1beta1.stub;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GaxProperties;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.retrying.RetrySettings;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.google.showcase.v1beta1.RepeatRequest;
+import com.google.showcase.v1beta1.RepeatResponse;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link ComplianceStub}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (localhost) and default port (7469) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of repeatDataBody to 30 seconds:
+ *
+ * <pre>{@code
+ * ComplianceStubSettings.Builder complianceSettingsBuilder = ComplianceStubSettings.newBuilder();
+ * complianceSettingsBuilder
+ *     .repeatDataBodySettings()
+ *     .setRetrySettings(
+ *         complianceSettingsBuilder
+ *             .repeatDataBodySettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * ComplianceStubSettings complianceSettings = complianceSettingsBuilder.build();
+ * }</pre>
+ */
+@BetaApi
+@Generated("by gapic-generator-java")
+public class ComplianceStubSettings extends StubSettings<ComplianceStubSettings> {
+  /** The default scopes of the service. */
+  private static final ImmutableList<String> DEFAULT_SERVICE_SCOPES =
+      ImmutableList.<String>builder().build();
+
+  private final UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataBodySettings;
+  private final UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataBodyInfoSettings;
+  private final UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataQuerySettings;
+  private final UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataSimplePathSettings;
+  private final UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataPathResourceSettings;
+  private final UnaryCallSettings<RepeatRequest, RepeatResponse>
+      repeatDataPathTrailingResourceSettings;
+
+  /** Returns the object with the settings used for calls to repeatDataBody. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataBodySettings() {
+    return repeatDataBodySettings;
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataBodyInfo. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataBodyInfoSettings() {
+    return repeatDataBodyInfoSettings;
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataQuery. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataQuerySettings() {
+    return repeatDataQuerySettings;
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataSimplePath. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataSimplePathSettings() {
+    return repeatDataSimplePathSettings;
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataPathResource. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataPathResourceSettings() {
+    return repeatDataPathResourceSettings;
+  }
+
+  /** Returns the object with the settings used for calls to repeatDataPathTrailingResource. */
+  public UnaryCallSettings<RepeatRequest, RepeatResponse> repeatDataPathTrailingResourceSettings() {
+    return repeatDataPathTrailingResourceSettings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public ComplianceStub createStub() throws IOException {
+    if (getTransportChannelProvider()
+        .getTransportName()
+        .equals(HttpJsonTransportChannel.getHttpJsonTransportName())) {
+      return HttpJsonComplianceStub.create(this);
+    }
+    throw new UnsupportedOperationException(
+        String.format(
+            "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return InstantiatingExecutorProvider.newBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return "localhost:7469";
+  }
+
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "localhost:7469";
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return DEFAULT_SERVICE_SCOPES;
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return InstantiatingHttpJsonChannelProvider.newBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return defaultHttpJsonTransportProviderBuilder().build();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return ApiClientHeaderProvider.newBuilder()
+        .setGeneratedLibToken(
+            "gapic", GaxProperties.getLibraryVersion(ComplianceStubSettings.class))
+        .setTransportToken(
+            GaxHttpJsonProperties.getHttpJsonTokenName(),
+            GaxHttpJsonProperties.getHttpJsonVersion());
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected ComplianceStubSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+
+    repeatDataBodySettings = settingsBuilder.repeatDataBodySettings().build();
+    repeatDataBodyInfoSettings = settingsBuilder.repeatDataBodyInfoSettings().build();
+    repeatDataQuerySettings = settingsBuilder.repeatDataQuerySettings().build();
+    repeatDataSimplePathSettings = settingsBuilder.repeatDataSimplePathSettings().build();
+    repeatDataPathResourceSettings = settingsBuilder.repeatDataPathResourceSettings().build();
+    repeatDataPathTrailingResourceSettings =
+        settingsBuilder.repeatDataPathTrailingResourceSettings().build();
+  }
+
+  /** Builder for ComplianceStubSettings. */
+  public static class Builder extends StubSettings.Builder<ComplianceStubSettings, Builder> {
+    private final ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders;
+    private final UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataBodySettings;
+    private final UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataBodyInfoSettings;
+    private final UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataQuerySettings;
+    private final UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataSimplePathSettings;
+    private final UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataPathResourceSettings;
+    private final UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataPathTrailingResourceSettings;
+    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
+        RETRYABLE_CODE_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
+          ImmutableMap.builder();
+      definitions.put("no_retry_codes", ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList()));
+      RETRYABLE_CODE_DEFINITIONS = definitions.build();
+    }
+
+    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
+      RetrySettings settings = null;
+      settings = RetrySettings.newBuilder().setRpcTimeoutMultiplier(1.0).build();
+      definitions.put("no_retry_params", settings);
+      RETRY_PARAM_DEFINITIONS = definitions.build();
+    }
+
+    protected Builder() {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(clientContext);
+
+      repeatDataBodySettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      repeatDataBodyInfoSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      repeatDataQuerySettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      repeatDataSimplePathSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      repeatDataPathResourceSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      repeatDataPathTrailingResourceSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+
+      unaryMethodSettingsBuilders =
+          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
+              repeatDataBodySettings,
+              repeatDataBodyInfoSettings,
+              repeatDataQuerySettings,
+              repeatDataSimplePathSettings,
+              repeatDataPathResourceSettings,
+              repeatDataPathTrailingResourceSettings);
+      initDefaults(this);
+    }
+
+    protected Builder(ComplianceStubSettings settings) {
+      super(settings);
+
+      repeatDataBodySettings = settings.repeatDataBodySettings.toBuilder();
+      repeatDataBodyInfoSettings = settings.repeatDataBodyInfoSettings.toBuilder();
+      repeatDataQuerySettings = settings.repeatDataQuerySettings.toBuilder();
+      repeatDataSimplePathSettings = settings.repeatDataSimplePathSettings.toBuilder();
+      repeatDataPathResourceSettings = settings.repeatDataPathResourceSettings.toBuilder();
+      repeatDataPathTrailingResourceSettings =
+          settings.repeatDataPathTrailingResourceSettings.toBuilder();
+
+      unaryMethodSettingsBuilders =
+          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
+              repeatDataBodySettings,
+              repeatDataBodyInfoSettings,
+              repeatDataQuerySettings,
+              repeatDataSimplePathSettings,
+              repeatDataPathResourceSettings,
+              repeatDataPathTrailingResourceSettings);
+    }
+
+    private static Builder createDefault() {
+      Builder builder = new Builder(((ClientContext) null));
+
+      builder.setTransportChannelProvider(defaultTransportChannelProvider());
+      builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
+      builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
+      builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
+
+      return initDefaults(builder);
+    }
+
+    private static Builder initDefaults(Builder builder) {
+      builder
+          .repeatDataBodySettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+
+      builder
+          .repeatDataBodyInfoSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+
+      builder
+          .repeatDataQuerySettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+
+      builder
+          .repeatDataSimplePathSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+
+      builder
+          .repeatDataPathResourceSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+
+      builder
+          .repeatDataPathTrailingResourceSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+
+      return builder;
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
+      return this;
+    }
+
+    public ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders() {
+      return unaryMethodSettingsBuilders;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataBody. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataBodySettings() {
+      return repeatDataBodySettings;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataBodyInfo. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataBodyInfoSettings() {
+      return repeatDataBodyInfoSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataQuery. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataQuerySettings() {
+      return repeatDataQuerySettings;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataSimplePath. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse> repeatDataSimplePathSettings() {
+      return repeatDataSimplePathSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataPathResource. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataPathResourceSettings() {
+      return repeatDataPathResourceSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to repeatDataPathTrailingResource. */
+    public UnaryCallSettings.Builder<RepeatRequest, RepeatResponse>
+        repeatDataPathTrailingResourceSettings() {
+      return repeatDataPathTrailingResourceSettings;
+    }
+
+    @Override
+    public ComplianceStubSettings build() throws IOException {
+      return new ComplianceStubSettings(this);
+    }
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/HttpJsonComplianceCallableFactory.golden b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/HttpJsonComplianceCallableFactory.golden
new file mode 100644
index 0000000000..7d6032778d
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/HttpJsonComplianceCallableFactory.golden
@@ -0,0 +1,68 @@
+package com.google.showcase.v1beta1.stub;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.httpjson.ApiMessage;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonCallableFactory;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.rpc.BatchingCallSettings;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.OperationCallSettings;
+import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.PagedCallSettings;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.api.gax.rpc.UnaryCallable;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * REST callable factory implementation for the Compliance service API.
+ *
+ * <p>This class is for advanced usage.
+ */
+@BetaApi
+@Generated("by gapic-generator-java")
+public class HttpJsonComplianceCallableFactory
+    implements HttpJsonStubCallableFactory<ApiMessage, BackgroundResource> {
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
+      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+      UnaryCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return HttpJsonCallableFactory.createUnaryCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT, PagedListResponseT>
+      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
+          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> callSettings,
+          ClientContext clientContext) {
+    return HttpJsonCallableFactory.createPagedCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
+      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+      BatchingCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return HttpJsonCallableFactory.createBatchingCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @BetaApi(
+      "The surface for long-running operations is not stable yet and may change in the future.")
+  @Override
+  public <RequestT, ResponseT, MetadataT>
+      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
+          HttpJsonCallSettings<RequestT, ApiMessage> httpJsonCallSettings,
+          OperationCallSettings<RequestT, ResponseT, MetadataT> callSettings,
+          ClientContext clientContext,
+          BackgroundResource operationsStub) {
+    return null;
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/HttpJsonComplianceStub.golden b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/HttpJsonComplianceStub.golden
new file mode 100644
index 0000000000..331e5bf961
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/composer/rest/goldens/HttpJsonComplianceStub.golden
@@ -0,0 +1,449 @@
+package com.google.showcase.v1beta1.stub;
+
+import com.google.api.client.http.HttpMethods;
+import com.google.api.core.BetaApi;
+import com.google.api.core.InternalApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.core.BackgroundResourceAggregation;
+import com.google.api.gax.httpjson.ApiMethodDescriptor;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.httpjson.ProtoMessageRequestFormatter;
+import com.google.api.gax.httpjson.ProtoMessageResponseParser;
+import com.google.api.gax.httpjson.ProtoRestSerializer;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.showcase.v1beta1.RepeatRequest;
+import com.google.showcase.v1beta1.RepeatResponse;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * REST stub implementation for the Compliance service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@BetaApi
+@Generated("by gapic-generator-java")
+@BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+public class HttpJsonComplianceStub extends ComplianceStub {
+  private static final ApiMethodDescriptor<RepeatRequest, RepeatResponse>
+      repeatDataBodyMethodDescriptor =
+          ApiMethodDescriptor.<RepeatRequest, RepeatResponse>newBuilder()
+              .setFullMethodName("google.showcase.v1beta1.Compliance/RepeatDataBody")
+              .setHttpMethod(HttpMethods.POST)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<RepeatRequest>newBuilder()
+                      .setPath(
+                          "/v1beta1/repeat:body",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(
+                          request ->
+                              ProtoRestSerializer.create().toBody("*", request.toBuilder().build()))
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<RepeatResponse>newBuilder()
+                      .setDefaultInstance(RepeatResponse.getDefaultInstance())
+                      .build())
+              .build();
+
+  private static final ApiMethodDescriptor<RepeatRequest, RepeatResponse>
+      repeatDataBodyInfoMethodDescriptor =
+          ApiMethodDescriptor.<RepeatRequest, RepeatResponse>newBuilder()
+              .setFullMethodName("google.showcase.v1beta1.Compliance/RepeatDataBodyInfo")
+              .setHttpMethod(HttpMethods.POST)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<RepeatRequest>newBuilder()
+                      .setPath(
+                          "/v1beta1/repeat:bodyinfo",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putQueryParam(fields, "name", request.getName());
+                            serializer.putQueryParam(
+                                fields, "serverVerify", request.getServerVerify());
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(
+                          request -> ProtoRestSerializer.create().toBody("info", request.getInfo()))
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<RepeatResponse>newBuilder()
+                      .setDefaultInstance(RepeatResponse.getDefaultInstance())
+                      .build())
+              .build();
+
+  private static final ApiMethodDescriptor<RepeatRequest, RepeatResponse>
+      repeatDataQueryMethodDescriptor =
+          ApiMethodDescriptor.<RepeatRequest, RepeatResponse>newBuilder()
+              .setFullMethodName("google.showcase.v1beta1.Compliance/RepeatDataQuery")
+              .setHttpMethod(HttpMethods.GET)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<RepeatRequest>newBuilder()
+                      .setPath(
+                          "/v1beta1/repeat:query",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putQueryParam(fields, "info", request.getInfo());
+                            serializer.putQueryParam(fields, "name", request.getName());
+                            serializer.putQueryParam(
+                                fields, "serverVerify", request.getServerVerify());
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(request -> null)
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<RepeatResponse>newBuilder()
+                      .setDefaultInstance(RepeatResponse.getDefaultInstance())
+                      .build())
+              .build();
+
+  private static final ApiMethodDescriptor<RepeatRequest, RepeatResponse>
+      repeatDataSimplePathMethodDescriptor =
+          ApiMethodDescriptor.<RepeatRequest, RepeatResponse>newBuilder()
+              .setFullMethodName("google.showcase.v1beta1.Compliance/RepeatDataSimplePath")
+              .setHttpMethod(HttpMethods.GET)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<RepeatRequest>newBuilder()
+                      .setPath(
+                          "/v1beta1/repeat/{info.fString}/{info.fInt32}/{info.fDouble}/{info.fBool}/{info.fKingdom}:simplepath",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            if (request.getInfo().hasFBool()) {
+                              serializer.putPathParam(
+                                  fields, "info.fBool", request.getInfo().getFBool());
+                            }
+                            serializer.putPathParam(
+                                fields, "info.fDouble", request.getInfo().getFDouble());
+                            serializer.putPathParam(
+                                fields, "info.fInt32", request.getInfo().getFInt32());
+                            serializer.putPathParam(
+                                fields, "info.fKingdom", request.getInfo().getFKingdom());
+                            serializer.putPathParam(
+                                fields, "info.fString", request.getInfo().getFString());
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putQueryParam(fields, "info", request.getInfo());
+                            serializer.putQueryParam(fields, "name", request.getName());
+                            serializer.putQueryParam(
+                                fields, "serverVerify", request.getServerVerify());
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(request -> null)
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<RepeatResponse>newBuilder()
+                      .setDefaultInstance(RepeatResponse.getDefaultInstance())
+                      .build())
+              .build();
+
+  private static final ApiMethodDescriptor<RepeatRequest, RepeatResponse>
+      repeatDataPathResourceMethodDescriptor =
+          ApiMethodDescriptor.<RepeatRequest, RepeatResponse>newBuilder()
+              .setFullMethodName("google.showcase.v1beta1.Compliance/RepeatDataPathResource")
+              .setHttpMethod(HttpMethods.GET)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<RepeatRequest>newBuilder()
+                      .setPath(
+                          "/v1beta1/repeat/{info.fString=first/*}/{info.fChild.fString=second/*}/bool/{info.fBool}:pathresource",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            if (request.getInfo().hasFBool()) {
+                              serializer.putPathParam(
+                                  fields, "info.fBool", request.getInfo().getFBool());
+                            }
+                            serializer.putPathParam(
+                                fields,
+                                "info.fChild.fString",
+                                request.getInfo().getFChild().getFString());
+                            serializer.putPathParam(
+                                fields, "info.fString", request.getInfo().getFString());
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putQueryParam(fields, "info", request.getInfo());
+                            serializer.putQueryParam(fields, "name", request.getName());
+                            serializer.putQueryParam(
+                                fields, "serverVerify", request.getServerVerify());
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(request -> null)
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<RepeatResponse>newBuilder()
+                      .setDefaultInstance(RepeatResponse.getDefaultInstance())
+                      .build())
+              .build();
+
+  private static final ApiMethodDescriptor<RepeatRequest, RepeatResponse>
+      repeatDataPathTrailingResourceMethodDescriptor =
+          ApiMethodDescriptor.<RepeatRequest, RepeatResponse>newBuilder()
+              .setFullMethodName(
+                  "google.showcase.v1beta1.Compliance/RepeatDataPathTrailingResource")
+              .setHttpMethod(HttpMethods.GET)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<RepeatRequest>newBuilder()
+                      .setPath(
+                          "/v1beta1/repeat/{info.fString=first/*}/{info.fChild.fString=second/**}:pathtrailingresource",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putPathParam(
+                                fields,
+                                "info.fChild.fString",
+                                request.getInfo().getFChild().getFString());
+                            serializer.putPathParam(
+                                fields, "info.fString", request.getInfo().getFString());
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<RepeatRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putQueryParam(fields, "info", request.getInfo());
+                            serializer.putQueryParam(fields, "name", request.getName());
+                            serializer.putQueryParam(
+                                fields, "serverVerify", request.getServerVerify());
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(request -> null)
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<RepeatResponse>newBuilder()
+                      .setDefaultInstance(RepeatResponse.getDefaultInstance())
+                      .build())
+              .build();
+
+  private final UnaryCallable<RepeatRequest, RepeatResponse> repeatDataBodyCallable;
+  private final UnaryCallable<RepeatRequest, RepeatResponse> repeatDataBodyInfoCallable;
+  private final UnaryCallable<RepeatRequest, RepeatResponse> repeatDataQueryCallable;
+  private final UnaryCallable<RepeatRequest, RepeatResponse> repeatDataSimplePathCallable;
+  private final UnaryCallable<RepeatRequest, RepeatResponse> repeatDataPathResourceCallable;
+  private final UnaryCallable<RepeatRequest, RepeatResponse> repeatDataPathTrailingResourceCallable;
+
+  private final BackgroundResource backgroundResources;
+  private final HttpJsonStubCallableFactory callableFactory;
+
+  public static final HttpJsonComplianceStub create(ComplianceStubSettings settings)
+      throws IOException {
+    return new HttpJsonComplianceStub(settings, ClientContext.create(settings));
+  }
+
+  public static final HttpJsonComplianceStub create(ClientContext clientContext)
+      throws IOException {
+    return new HttpJsonComplianceStub(ComplianceStubSettings.newBuilder().build(), clientContext);
+  }
+
+  public static final HttpJsonComplianceStub create(
+      ClientContext clientContext, HttpJsonStubCallableFactory callableFactory) throws IOException {
+    return new HttpJsonComplianceStub(
+        ComplianceStubSettings.newBuilder().build(), clientContext, callableFactory);
+  }
+
+  /**
+   * Constructs an instance of HttpJsonComplianceStub, using the given settings. This is protected
+   * so that it is easy to make a subclass, but otherwise, the static factory methods should be
+   * preferred.
+   */
+  protected HttpJsonComplianceStub(ComplianceStubSettings settings, ClientContext clientContext)
+      throws IOException {
+    this(settings, clientContext, new HttpJsonComplianceCallableFactory());
+  }
+
+  /**
+   * Constructs an instance of HttpJsonComplianceStub, using the given settings. This is protected
+   * so that it is easy to make a subclass, but otherwise, the static factory methods should be
+   * preferred.
+   */
+  protected HttpJsonComplianceStub(
+      ComplianceStubSettings settings,
+      ClientContext clientContext,
+      HttpJsonStubCallableFactory callableFactory)
+      throws IOException {
+    this.callableFactory = callableFactory;
+
+    HttpJsonCallSettings<RepeatRequest, RepeatResponse> repeatDataBodyTransportSettings =
+        HttpJsonCallSettings.<RepeatRequest, RepeatResponse>newBuilder()
+            .setMethodDescriptor(repeatDataBodyMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<RepeatRequest, RepeatResponse> repeatDataBodyInfoTransportSettings =
+        HttpJsonCallSettings.<RepeatRequest, RepeatResponse>newBuilder()
+            .setMethodDescriptor(repeatDataBodyInfoMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<RepeatRequest, RepeatResponse> repeatDataQueryTransportSettings =
+        HttpJsonCallSettings.<RepeatRequest, RepeatResponse>newBuilder()
+            .setMethodDescriptor(repeatDataQueryMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<RepeatRequest, RepeatResponse> repeatDataSimplePathTransportSettings =
+        HttpJsonCallSettings.<RepeatRequest, RepeatResponse>newBuilder()
+            .setMethodDescriptor(repeatDataSimplePathMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<RepeatRequest, RepeatResponse> repeatDataPathResourceTransportSettings =
+        HttpJsonCallSettings.<RepeatRequest, RepeatResponse>newBuilder()
+            .setMethodDescriptor(repeatDataPathResourceMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<RepeatRequest, RepeatResponse>
+        repeatDataPathTrailingResourceTransportSettings =
+            HttpJsonCallSettings.<RepeatRequest, RepeatResponse>newBuilder()
+                .setMethodDescriptor(repeatDataPathTrailingResourceMethodDescriptor)
+                .build();
+
+    this.repeatDataBodyCallable =
+        callableFactory.createUnaryCallable(
+            repeatDataBodyTransportSettings, settings.repeatDataBodySettings(), clientContext);
+    this.repeatDataBodyInfoCallable =
+        callableFactory.createUnaryCallable(
+            repeatDataBodyInfoTransportSettings,
+            settings.repeatDataBodyInfoSettings(),
+            clientContext);
+    this.repeatDataQueryCallable =
+        callableFactory.createUnaryCallable(
+            repeatDataQueryTransportSettings, settings.repeatDataQuerySettings(), clientContext);
+    this.repeatDataSimplePathCallable =
+        callableFactory.createUnaryCallable(
+            repeatDataSimplePathTransportSettings,
+            settings.repeatDataSimplePathSettings(),
+            clientContext);
+    this.repeatDataPathResourceCallable =
+        callableFactory.createUnaryCallable(
+            repeatDataPathResourceTransportSettings,
+            settings.repeatDataPathResourceSettings(),
+            clientContext);
+    this.repeatDataPathTrailingResourceCallable =
+        callableFactory.createUnaryCallable(
+            repeatDataPathTrailingResourceTransportSettings,
+            settings.repeatDataPathTrailingResourceSettings(),
+            clientContext);
+
+    this.backgroundResources =
+        new BackgroundResourceAggregation(clientContext.getBackgroundResources());
+  }
+
+  @InternalApi
+  public static List<ApiMethodDescriptor> getMethodDescriptors() {
+    List<ApiMethodDescriptor> methodDescriptors = new ArrayList<>();
+    methodDescriptors.add(repeatDataBodyMethodDescriptor);
+    methodDescriptors.add(repeatDataBodyInfoMethodDescriptor);
+    methodDescriptors.add(repeatDataQueryMethodDescriptor);
+    methodDescriptors.add(repeatDataSimplePathMethodDescriptor);
+    methodDescriptors.add(repeatDataPathResourceMethodDescriptor);
+    methodDescriptors.add(repeatDataPathTrailingResourceMethodDescriptor);
+    return methodDescriptors;
+  }
+
+  @Override
+  public UnaryCallable<RepeatRequest, RepeatResponse> repeatDataBodyCallable() {
+    return repeatDataBodyCallable;
+  }
+
+  @Override
+  public UnaryCallable<RepeatRequest, RepeatResponse> repeatDataBodyInfoCallable() {
+    return repeatDataBodyInfoCallable;
+  }
+
+  @Override
+  public UnaryCallable<RepeatRequest, RepeatResponse> repeatDataQueryCallable() {
+    return repeatDataQueryCallable;
+  }
+
+  @Override
+  public UnaryCallable<RepeatRequest, RepeatResponse> repeatDataSimplePathCallable() {
+    return repeatDataSimplePathCallable;
+  }
+
+  @Override
+  public UnaryCallable<RepeatRequest, RepeatResponse> repeatDataPathResourceCallable() {
+    return repeatDataPathResourceCallable;
+  }
+
+  @Override
+  public UnaryCallable<RepeatRequest, RepeatResponse> repeatDataPathTrailingResourceCallable() {
+    return repeatDataPathTrailingResourceCallable;
+  }
+
+  @Override
+  public final void close() {
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
+  }
+
+  @Override
+  public void shutdown() {
+    backgroundResources.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return backgroundResources.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return backgroundResources.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    backgroundResources.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return backgroundResources.awaitTermination(duration, unit);
+  }
+}
diff --git a/src/test/java/com/google/api/generator/gapic/composer/samplecode/SampleCodeWriterTest.java b/src/test/java/com/google/api/generator/gapic/composer/samplecode/SampleCodeWriterTest.java
index 4e5be8cd19..d9456c7dcf 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/samplecode/SampleCodeWriterTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/samplecode/SampleCodeWriterTest.java
@@ -22,9 +22,9 @@
 import com.google.api.generator.engine.ast.ExprStatement;
 import com.google.api.generator.engine.ast.MethodInvocationExpr;
 import com.google.api.generator.engine.ast.PrimitiveValue;
-import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.Statement;
 import com.google.api.generator.engine.ast.TryCatchStatement;
+import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.ValueExpr;
 import com.google.api.generator.engine.ast.Variable;
 import com.google.api.generator.engine.ast.VariableExpr;
@@ -34,47 +34,49 @@
 public class SampleCodeWriterTest {
   @Test
   public void writeSampleCode_statements() {
-    TypeNode settingType = TypeNode.withReference(ConcreteReference.withClazz(ClientSettings.class));
+    TypeNode settingType =
+        TypeNode.withReference(ConcreteReference.withClazz(ClientSettings.class));
     Variable aVar = Variable.builder().setName("clientSettings").setType(settingType).build();
     VariableExpr aVarExpr = VariableExpr.withVariable(aVar);
-    MethodInvocationExpr aValueExpr = MethodInvocationExpr.builder()
-        .setExprReferenceExpr(MethodInvocationExpr.builder()
-        .setMethodName("newBuilder")
-        .setStaticReferenceType(settingType)
-        .build())
-        .setReturnType(settingType)
-        .setMethodName("build")
-        .build();
-    AssignmentExpr assignmentExpr = AssignmentExpr.builder()
-        .setVariableExpr(aVarExpr.toBuilder().setIsDecl(true).build())
-        .setValueExpr(aValueExpr)
-        .build();
-    Statement sampleStatement = TryCatchStatement.builder()
-        .setTryResourceExpr(createAssignmentExpr("aBool", "false", TypeNode.BOOLEAN))
-        .setTryBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("x", "3", TypeNode.INT))))
-        .setIsSampleCode(true)
-        .build();
-    String result = SampleCodeWriter.write(
-        ExprStatement.withExpr(assignmentExpr),
-            sampleStatement);
-    String expected = "ClientSettings clientSettings = ClientSettings.newBuilder().build();\n"
-        + "try (boolean aBool = false) {\n"
-        + "  int x = 3;\n"
-        + "}";
+    MethodInvocationExpr aValueExpr =
+        MethodInvocationExpr.builder()
+            .setExprReferenceExpr(
+                MethodInvocationExpr.builder()
+                    .setMethodName("newBuilder")
+                    .setStaticReferenceType(settingType)
+                    .build())
+            .setReturnType(settingType)
+            .setMethodName("build")
+            .build();
+    AssignmentExpr assignmentExpr =
+        AssignmentExpr.builder()
+            .setVariableExpr(aVarExpr.toBuilder().setIsDecl(true).build())
+            .setValueExpr(aValueExpr)
+            .build();
+    Statement sampleStatement =
+        TryCatchStatement.builder()
+            .setTryResourceExpr(createAssignmentExpr("aBool", "false", TypeNode.BOOLEAN))
+            .setTryBody(
+                Arrays.asList(ExprStatement.withExpr(createAssignmentExpr("x", "3", TypeNode.INT))))
+            .setIsSampleCode(true)
+            .build();
+    String result = SampleCodeWriter.write(ExprStatement.withExpr(assignmentExpr), sampleStatement);
+    String expected =
+        "ClientSettings clientSettings = ClientSettings.newBuilder().build();\n"
+            + "try (boolean aBool = false) {\n"
+            + "  int x = 3;\n"
+            + "}";
     assertEquals(expected, result);
   }
 
   private AssignmentExpr createAssignmentExpr(String varName, String varValue, TypeNode type) {
     Variable variable = Variable.builder().setName(varName).setType(type).build();
     VariableExpr variableExpr =
-        VariableExpr.builder()
-            .setVariable(variable)
-            .setIsDecl(true)
-            .build();
+        VariableExpr.builder().setVariable(variable).setIsDecl(true).build();
     return AssignmentExpr.builder()
         .setVariableExpr(variableExpr)
-        .setValueExpr(ValueExpr.withValue(PrimitiveValue.builder().setType(type).setValue(varValue).build()))
+        .setValueExpr(
+            ValueExpr.withValue(PrimitiveValue.builder().setType(type).setValue(varValue).build()))
         .build();
   }
-
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposerTest.java
index e360b1eb3a..59eb3536be 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientSampleCodeComposerTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.gapic.composer.samplecode;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
 
 import com.google.api.generator.engine.ast.ConcreteReference;
@@ -32,7 +32,6 @@
 import com.google.api.generator.gapic.protoparser.Parser;
 import com.google.api.generator.testutils.LineFormatter;
 import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.showcase.v1beta1.EchoOuterClass;
 import java.util.Arrays;
 import java.util.Collections;
@@ -47,6 +46,7 @@ public class ServiceClientSampleCodeComposerTest {
   private static final String SHOWCASE_PACKAGE_NAME = "com.google.showcase.v1beta1";
   private static final String LRO_PACKAGE_NAME = "com.google.longrunning";
   private static final String PROTO_PACKAGE_NAME = "com.google.protobuf";
+  private static final String PAGINATED_FIELD_NAME = "page_size";
 
   // =============================== Class Header Sample Code ===============================//
   @Test
@@ -54,7 +54,6 @@ public void composeClassHeaderMethodSampleCode_unaryRpc() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
-    ServiceDescriptor echoService = echoFileDescriptor.getServices().get(0);
     Set<ResourceName> outputResourceNames = new HashSet<>();
     List<Service> services =
         Parser.parseService(
@@ -1005,7 +1004,7 @@ public void validComposeRpcMethodHeaderSampleCode_pagedRpcWithMultipleMethodArgu
             .setMethodSignatures(Arrays.asList(arguments))
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     Reference repeatedResponseReference =
         VaporReference.builder().setName("Content").setPakkage(SHOWCASE_PACKAGE_NAME).build();
@@ -1078,7 +1077,7 @@ public void validComposeRpcMethodHeaderSampleCode_pagedRpcWithNoMethodArguments(
             .setMethodSignatures(Arrays.asList(arguments))
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     Reference repeatedResponseReference =
         VaporReference.builder().setName("Content").setPakkage(SHOWCASE_PACKAGE_NAME).build();
@@ -1148,7 +1147,7 @@ public void invalidComposeRpcMethodHeaderSampleCode_noMatchedRepeatedResponseTyp
             .setMethodSignatures(Arrays.asList(methodArguments))
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     assertThrows(
         NullPointerException.class,
@@ -1187,7 +1186,7 @@ public void invalidComposeRpcMethodHeaderSampleCode_noRepeatedResponseTypeInPage
             .setMethodSignatures(Arrays.asList(methodArguments))
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     Field responseField =
         Field.builder()
@@ -1439,7 +1438,7 @@ public void validComposeRpcDefaultMethodHeaderSampleCode_isPagedMethod() {
             .setInputType(inputType)
             .setOutputType(outputType)
             .setMethodSignatures(Collections.emptyList())
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     String results =
         ServiceClientSampleCodeComposer.composeRpcDefaultMethodHeaderSampleCode(
@@ -1489,7 +1488,7 @@ public void invalidComposeRpcDefaultMethodHeaderSampleCode_isPagedMethod() {
             .setInputType(inputType)
             .setOutputType(outputType)
             .setMethodSignatures(Collections.emptyList())
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     assertThrows(
         NullPointerException.class,
@@ -1835,7 +1834,7 @@ public void validComposePagedCallableMethodHeaderSampleCode() {
             .setName("PagedExpand")
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     String results =
         ServiceClientSampleCodeComposer.composePagedCallableMethodHeaderSampleCode(
@@ -1887,7 +1886,7 @@ public void invalidComposePagedCallableMethodHeaderSampleCode_inputTypeNotExistI
             .setName("PagedExpand")
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     assertThrows(
         NullPointerException.class,
@@ -1924,7 +1923,7 @@ public void invalidComposePagedCallableMethodHeaderSampleCode_noExistMethodRespo
             .setName("PagedExpand")
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     assertThrows(
         NullPointerException.class,
@@ -1961,7 +1960,7 @@ public void invalidComposePagedCallableMethodHeaderSampleCode_noRepeatedResponse
             .setName("PagedExpand")
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     Field responseField = Field.builder().setName("response").setType(TypeNode.STRING).build();
     Message noRepeatedResponseMessage =
@@ -2449,7 +2448,7 @@ public void validComposeRegularCallableMethodHeaderSampleCode_pageRpc() {
             .setInputType(inputType)
             .setOutputType(outputType)
             .setMethodSignatures(Collections.emptyList())
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     String results =
         ServiceClientSampleCodeComposer.composeRegularCallableMethodHeaderSampleCode(
@@ -2539,7 +2538,7 @@ public void invalidComposeRegularCallableMethodHeaderSampleCode_noExistMethodRes
             .setName("PagedExpand")
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     assertThrows(
         NullPointerException.class,
@@ -2576,7 +2575,7 @@ public void invalidComposeRegularCallableMethodHeaderSampleCode_noRepeatedRespon
             .setName("PagedExpand")
             .setInputType(inputType)
             .setOutputType(outputType)
-            .setIsPaged(true)
+            .setPageSizeFieldName(PAGINATED_FIELD_NAME)
             .build();
     Field responseField = Field.builder().setName("response").setType(TypeNode.STRING).build();
     Message noRepeatedResponseMessage =
diff --git a/src/test/java/com/google/api/generator/gapic/composer/samplecode/SettingsSampleCodeComposerTest.java b/src/test/java/com/google/api/generator/gapic/composer/samplecode/SettingsSampleCodeComposerTest.java
index b7438e4732..a62d57275c 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/samplecode/SettingsSampleCodeComposerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/samplecode/SettingsSampleCodeComposerTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.gapic.composer.samplecode;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.VaporReference;
@@ -25,56 +25,68 @@
 public class SettingsSampleCodeComposerTest {
   @Test
   public void composeSettingsSampleCode_noMethods() {
-    TypeNode classType = TypeNode.withReference(VaporReference.builder()
-    .setName("EchoSettings")
-    .setPakkage("com.google.showcase.v1beta1")
-    .build());
-    Optional<String> results =  SettingsSampleCodeComposer.composeSampleCode(Optional.empty(), "EchoSettings", classType);
+    TypeNode classType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoSettings")
+                .setPakkage("com.google.showcase.v1beta1")
+                .build());
+    Optional<String> results =
+        SettingsSampleCodeComposer.composeSampleCode(Optional.empty(), "EchoSettings", classType);
     assertEquals(results, Optional.empty());
   }
 
   @Test
   public void composeSettingsSampleCode_serviceSettingsClass() {
-    TypeNode classType = TypeNode.withReference(VaporReference.builder()
-        .setName("EchoSettings")
-        .setPakkage("com.google.showcase.v1beta1")
-        .build());
-    Optional<String> results = SettingsSampleCodeComposer.composeSampleCode(Optional.of("Echo"), "EchoSettings", classType);
-    String expected = LineFormatter.lines(
-        "EchoSettings.Builder echoSettingsBuilder = EchoSettings.newBuilder();\n",
-        "echoSettingsBuilder\n",
-        "    .echoSettings()\n",
-        "    .setRetrySettings(\n",
-        "        echoSettingsBuilder\n",
-        "            .echoSettings()\n",
-        "            .getRetrySettings()\n",
-        "            .toBuilder()\n",
-        "            .setTotalTimeout(Duration.ofSeconds(30))\n",
-        "            .build());\n",
-        "EchoSettings echoSettings = echoSettingsBuilder.build();");
+    TypeNode classType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoSettings")
+                .setPakkage("com.google.showcase.v1beta1")
+                .build());
+    Optional<String> results =
+        SettingsSampleCodeComposer.composeSampleCode(
+            Optional.of("Echo"), "EchoSettings", classType);
+    String expected =
+        LineFormatter.lines(
+            "EchoSettings.Builder echoSettingsBuilder = EchoSettings.newBuilder();\n",
+            "echoSettingsBuilder\n",
+            "    .echoSettings()\n",
+            "    .setRetrySettings(\n",
+            "        echoSettingsBuilder\n",
+            "            .echoSettings()\n",
+            "            .getRetrySettings()\n",
+            "            .toBuilder()\n",
+            "            .setTotalTimeout(Duration.ofSeconds(30))\n",
+            "            .build());\n",
+            "EchoSettings echoSettings = echoSettingsBuilder.build();");
     assertEquals(results.get(), expected);
   }
 
   @Test
   public void composeSettingsSampleCode_serviceStubClass() {
-    TypeNode classType = TypeNode.withReference(VaporReference.builder()
-        .setName("EchoStubSettings")
-        .setPakkage("com.google.showcase.v1beta1")
-        .build());
-    Optional<String> results = SettingsSampleCodeComposer.composeSampleCode(Optional.of("Echo"), "EchoSettings", classType);
-    String expected = LineFormatter.lines(
-        "EchoStubSettings.Builder echoSettingsBuilder = EchoStubSettings.newBuilder();\n",
-        "echoSettingsBuilder\n",
-        "    .echoSettings()\n",
-        "    .setRetrySettings(\n",
-        "        echoSettingsBuilder\n",
-        "            .echoSettings()\n",
-        "            .getRetrySettings()\n",
-        "            .toBuilder()\n",
-        "            .setTotalTimeout(Duration.ofSeconds(30))\n",
-        "            .build());\n",
-        "EchoStubSettings echoSettings = echoSettingsBuilder.build();");
+    TypeNode classType =
+        TypeNode.withReference(
+            VaporReference.builder()
+                .setName("EchoStubSettings")
+                .setPakkage("com.google.showcase.v1beta1")
+                .build());
+    Optional<String> results =
+        SettingsSampleCodeComposer.composeSampleCode(
+            Optional.of("Echo"), "EchoSettings", classType);
+    String expected =
+        LineFormatter.lines(
+            "EchoStubSettings.Builder echoSettingsBuilder = EchoStubSettings.newBuilder();\n",
+            "echoSettingsBuilder\n",
+            "    .echoSettings()\n",
+            "    .setRetrySettings(\n",
+            "        echoSettingsBuilder\n",
+            "            .echoSettings()\n",
+            "            .getRetrySettings()\n",
+            "            .toBuilder()\n",
+            "            .setTotalTimeout(Duration.ofSeconds(30))\n",
+            "            .build());\n",
+            "EchoStubSettings echoSettings = echoSettingsBuilder.build();");
     assertEquals(results.get(), expected);
   }
-
 }
diff --git a/src/test/java/com/google/api/generator/gapic/composer/utils/PackageCheckerTest.java b/src/test/java/com/google/api/generator/gapic/composer/utils/PackageCheckerTest.java
index 9cde282e24..c8f220f65e 100644
--- a/src/test/java/com/google/api/generator/gapic/composer/utils/PackageCheckerTest.java
+++ b/src/test/java/com/google/api/generator/gapic/composer/utils/PackageCheckerTest.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.gapic.composer.utils;
 
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 
diff --git a/src/test/java/com/google/api/generator/gapic/model/GapicServiceConfigTest.java b/src/test/java/com/google/api/generator/gapic/model/GapicServiceConfigTest.java
index 61f9e45b02..6c5a0846e7 100644
--- a/src/test/java/com/google/api/generator/gapic/model/GapicServiceConfigTest.java
+++ b/src/test/java/com/google/api/generator/gapic/model/GapicServiceConfigTest.java
@@ -15,14 +15,13 @@
 package com.google.api.generator.gapic.model;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.gapic.protoparser.Parser;
 import com.google.api.generator.gapic.protoparser.ServiceConfigParser;
 import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.protobuf.util.Durations;
 import com.google.rpc.Code;
 import com.google.showcase.v1beta1.EchoOuterClass;
@@ -45,7 +44,6 @@ public class GapicServiceConfigTest {
   @Test
   public void serviceConfig_noConfigsFound() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Service service = parseService(echoFileDescriptor);
 
     String jsonFilename = "retrying_grpc_service_config.json";
@@ -74,7 +72,6 @@ public void serviceConfig_noConfigsFound() {
   @Test
   public void serviceConfig_basic() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Service service = parseService(echoFileDescriptor);
 
     String jsonFilename = "showcase_grpc_service_config.json";
@@ -129,7 +126,6 @@ public void serviceConfig_basic() {
   @Test
   public void serviceConfig_withBatchingSettings() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Service service = parseService(echoFileDescriptor);
 
     String jsonFilename = "showcase_grpc_service_config.json";
@@ -203,12 +199,10 @@ public void serviceConfig_withBatchingSettings() {
   @Test
   public void serviceConfig_withLroRetrySettings() {
     FileDescriptor echoFileDescriptor = EchoOuterClass.getDescriptor();
-    ServiceDescriptor echoServiceDescriptor = echoFileDescriptor.getServices().get(0);
     Service service = parseService(echoFileDescriptor);
 
     String jsonFilename = "showcase_grpc_service_config.json";
     Path jsonPath = Paths.get(TESTDATA_DIRECTORY, jsonFilename);
-    Optional<List<GapicBatchingSettings>> batchingSettingsOpt = Optional.empty();
 
     // Construct LRO retry settings.
     GapicLroRetrySettings origLroRetrySetting =
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/protoparser/BUILD.bazel
index abf6a5e00a..f15a3d1a6e 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/BUILD.bazel
@@ -41,6 +41,7 @@ filegroup(
         "//src/main/java/com/google/api/generator/gapic/model",
         "//src/main/java/com/google/api/generator/gapic/protoparser",
         "//src/main/java/com/google/api/generator/gapic/utils",
+        "//src/test/java/com/google/api/generator/gapic/testdata:bookshop_java_proto",
         "//src/test/java/com/google/api/generator/gapic/testdata:showcase_java_proto",
         "//src/test/java/com/google/api/generator/gapic/testdata:testgapic_java_proto",
         "@com_google_api_api_common//jar",
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParserTest.java
index 92ba2e5094..3d3c16dc6e 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/BatchingSettingsConfigParserTest.java
@@ -15,9 +15,9 @@
 package com.google.api.generator.gapic.protoparser;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.gapic.model.GapicBatchingSettings;
 import java.nio.file.Path;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParserTest.java
index 111abd1a80..1db960c0ab 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParserTest.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.gapic.model.GapicLanguageSettings;
 import java.nio.file.Path;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParserTest.java
index 262b266f53..664b7d2e69 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/GapicLroRetrySettingsParserTest.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 
 import com.google.api.generator.gapic.model.GapicLroRetrySettings;
 import java.nio.file.Path;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/HttpRuleParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/HttpRuleParserTest.java
index 59a0775b69..31fc531555 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/HttpRuleParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/HttpRuleParserTest.java
@@ -15,19 +15,19 @@
 package com.google.api.generator.gapic.protoparser;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 
+import com.google.api.generator.gapic.model.HttpBindings;
+import com.google.api.generator.gapic.model.HttpBindings.HttpBinding;
 import com.google.api.generator.gapic.model.Message;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.MethodDescriptor;
 import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.showcase.v1beta1.TestingOuterClass;
-import java.util.List;
 import java.util.Map;
-import java.util.Optional;
+import java.util.stream.Collectors;
 import org.junit.Test;
 
 public class HttpRuleParserTest {
@@ -42,16 +42,18 @@ public void parseHttpAnnotation_basic() {
     // CreateSession method.
     MethodDescriptor rpcMethod = testingService.getMethods().get(0);
     Message inputMessage = messages.get("com.google.showcase.v1beta1.CreateSessionRequest");
-    Optional<List<String>> httpBindingsOpt =
-        HttpRuleParser.parseHttpBindings(rpcMethod, inputMessage, messages);
-    assertFalse(httpBindingsOpt.isPresent());
+    HttpBindings httpBindings = HttpRuleParser.parse(rpcMethod, inputMessage, messages);
+    assertTrue(httpBindings.pathParameters().isEmpty());
 
     // GetSession method.
     rpcMethod = testingService.getMethods().get(1);
     inputMessage = messages.get("com.google.showcase.v1beta1.GetSessionRequest");
-    httpBindingsOpt = HttpRuleParser.parseHttpBindings(rpcMethod, inputMessage, messages);
-    assertTrue(httpBindingsOpt.isPresent());
-    assertThat(httpBindingsOpt.get()).containsExactly("name");
+    httpBindings = HttpRuleParser.parse(rpcMethod, inputMessage, messages);
+    assertThat(
+            httpBindings.pathParameters().stream()
+                .map(HttpBinding::name)
+                .collect(Collectors.toList()))
+        .containsExactly("name");
   }
 
   @Test
@@ -66,10 +68,11 @@ public void parseHttpAnnotation_multipleBindings() {
     MethodDescriptor rpcMethod =
         testingService.getMethods().get(testingService.getMethods().size() - 1);
     Message inputMessage = messages.get("com.google.showcase.v1beta1.VerifyTestRequest");
-    Optional<List<String>> httpBindingsOpt =
-        HttpRuleParser.parseHttpBindings(rpcMethod, inputMessage, messages);
-    assertTrue(httpBindingsOpt.isPresent());
-    assertThat(httpBindingsOpt.get())
+    HttpBindings httpBindings = HttpRuleParser.parse(rpcMethod, inputMessage, messages);
+    assertThat(
+            httpBindings.pathParameters().stream()
+                .map(HttpBinding::name)
+                .collect(Collectors.toList()))
         .containsExactly("answer", "foo", "name", "test_to_verify.name", "type");
   }
 
@@ -86,7 +89,6 @@ public void parseHttpAnnotation_missingFieldFromMessage() {
         testingService.getMethods().get(testingService.getMethods().size() - 1);
     Message inputMessage = messages.get("com.google.showcase.v1beta1.CreateSessionRequest");
     assertThrows(
-        IllegalStateException.class,
-        () -> HttpRuleParser.parseHttpBindings(rpcMethod, inputMessage, messages));
+        IllegalStateException.class, () -> HttpRuleParser.parse(rpcMethod, inputMessage, messages));
   }
 }
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/MethodSignatureParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/MethodSignatureParserTest.java
index 4f141f6125..68a2bbc66b 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/MethodSignatureParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/MethodSignatureParserTest.java
@@ -14,16 +14,13 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.VaporReference;
 import com.google.api.generator.gapic.model.Field;
 import com.google.api.generator.gapic.model.MethodArgument;
-import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.ServiceDescriptor;
-import com.google.testgapic.v1beta1.LockerProto;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
@@ -31,20 +28,9 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.Collectors;
-import org.junit.Before;
 import org.junit.Test;
 
 public class MethodSignatureParserTest {
-  private static final String MAIN_PACKAGE = "com.google.testgapic.v1beta1";
-
-  private ServiceDescriptor lockerService;
-  private FileDescriptor lockerServiceFileDescriptor;
-
-  @Before
-  public void setUp() {
-    lockerServiceFileDescriptor = LockerProto.getDescriptor();
-    lockerService = lockerServiceFileDescriptor.getServices().get(0);
-  }
 
   @Test
   public void flattenMethodSignatures_basic() {
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/ParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/ParserTest.java
index b19aa30b92..9026437b6d 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/ParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/ParserTest.java
@@ -15,10 +15,10 @@
 package com.google.api.generator.gapic.protoparser;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.Reference;
@@ -30,6 +30,8 @@
 import com.google.api.generator.gapic.model.MethodArgument;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.model.ResourceReference;
+import com.google.api.generator.gapic.model.Transport;
+import com.google.bookshop.v1beta1.BookshopProto;
 import com.google.common.collect.ImmutableList;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.MethodDescriptor;
@@ -96,6 +98,17 @@ public void parseMessages_basic() {
         echoResponseMessage, messageTypes.get("com.google.showcase.v1beta1." + echoResponseName));
   }
 
+  @Test
+  public void parseMessages_fieldNameConflicts() {
+    FileDescriptor bookshopFileDescriptor = BookshopProto.getDescriptor();
+    Map<String, Message> messageTypes = Parser.parseMessages(bookshopFileDescriptor);
+    Message requestMessage = messageTypes.get("com.google.bookshop.v1beta1.GetBookRequest");
+    // Check that field names have been changed.
+    assertThat(requestMessage.fieldMap()).containsKey("books_count1");
+    assertThat(requestMessage.fieldMap()).containsKey("books_list2");
+    assertThat(requestMessage.fieldMap()).containsKey("books3");
+  }
+
   @Test
   public void parseMethods_basic() {
     Map<String, Message> messageTypes = Parser.parseMessages(echoFileDescriptor);
@@ -108,9 +121,10 @@ public void parseMethods_basic() {
             messageTypes,
             resourceNames,
             Optional.empty(),
-            outputResourceNames);
+            outputResourceNames,
+            Transport.GRPC);
 
-    assertEquals(9, methods.size());
+    assertEquals(10, methods.size());
 
     // Methods should appear in the same order as in the protobuf file.
     Method echoMethod = methods.get(0);
@@ -165,9 +179,10 @@ public void parseMethods_basicLro() {
             messageTypes,
             resourceNames,
             Optional.empty(),
-            outputResourceNames);
+            outputResourceNames,
+            Transport.GRPC);
 
-    assertEquals(9, methods.size());
+    assertEquals(10, methods.size());
 
     // Methods should appear in the same order as in the protobuf file.
     Method waitMethod = methods.get(7);
@@ -209,14 +224,6 @@ public void parseMethodSignatures_empty() {
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
 
-    List<Method> methods =
-        Parser.parseMethods(
-            echoService,
-            ECHO_PACKAGE,
-            messageTypes,
-            resourceNames,
-            Optional.empty(),
-            outputResourceNames);
     assertThat(
             MethodSignatureParser.parseMethodSignatures(
                 methodDescriptor,
@@ -238,14 +245,6 @@ public void parseMethodSignatures_validArgstAndEmptyString() {
     Map<String, ResourceName> resourceNames = Parser.parseResourceNames(echoFileDescriptor);
     Set<ResourceName> outputResourceNames = new HashSet<>();
 
-    List<Method> methods =
-        Parser.parseMethods(
-            echoService,
-            ECHO_PACKAGE,
-            messageTypes,
-            resourceNames,
-            Optional.empty(),
-            outputResourceNames);
     List<List<MethodArgument>> methodArgs =
         MethodSignatureParser.parseMethodSignatures(
             methodDescriptor,
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/PluginArgumentParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/PluginArgumentParserTest.java
index f6a55f0602..2dcaa298cf 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/PluginArgumentParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/PluginArgumentParserTest.java
@@ -14,9 +14,9 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import java.util.Arrays;
 import org.junit.Test;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/ResourceNameParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/ResourceNameParserTest.java
index 36395ec10b..04b6622b5a 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/ResourceNameParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/ResourceNameParserTest.java
@@ -15,10 +15,10 @@
 package com.google.api.generator.gapic.protoparser;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.ast.ConcreteReference;
 import com.google.api.generator.engine.ast.TypeNode;
@@ -26,7 +26,6 @@
 import com.google.api.generator.gapic.utils.ResourceNameConstants;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.testgapic.v1beta1.BadMessageResnameDefProto;
 import com.google.testgapic.v1beta1.LockerProto;
 import java.util.List;
@@ -38,13 +37,11 @@
 public class ResourceNameParserTest {
   private static final String MAIN_PACKAGE = "com.google.testgapic.v1beta1";
 
-  private ServiceDescriptor lockerService;
   private FileDescriptor lockerServiceFileDescriptor;
 
   @Before
   public void setUp() {
     lockerServiceFileDescriptor = LockerProto.getDescriptor();
-    lockerService = lockerServiceFileDescriptor.getServices().get(0);
   }
 
   @Test
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/ResourceReferenceParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/ResourceReferenceParserTest.java
index 346431d2c5..5056192c1c 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/ResourceReferenceParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/ResourceReferenceParserTest.java
@@ -14,16 +14,15 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.VaporReference;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.utils.ResourceNameConstants;
 import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.testgapic.v1beta1.LockerProto;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -35,13 +34,11 @@
 public class ResourceReferenceParserTest {
   private static final String MAIN_PACKAGE = "com.google.testgapic.v1beta1";
 
-  private ServiceDescriptor lockerService;
   private FileDescriptor lockerServiceFileDescriptor;
 
   @Before
   public void setUp() {
     lockerServiceFileDescriptor = LockerProto.getDescriptor();
-    lockerService = lockerServiceFileDescriptor.getServices().get(0);
   }
 
   @Test
@@ -173,7 +170,6 @@ public void resolvePackages_resourcePackageIsSubpackageOfService() {
 
   @Test
   public void resolvePackages_resourcePackageIsSameAsService() {
-    String resourcePackage = "com.google.testgapic.v1beta1.common";
     assertEquals(MAIN_PACKAGE, ResourceReferenceParser.resolvePackages(MAIN_PACKAGE, MAIN_PACKAGE));
   }
 
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/ServiceConfigParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/ServiceConfigParserTest.java
index d5688d545d..eb69209242 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/ServiceConfigParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/ServiceConfigParserTest.java
@@ -14,9 +14,9 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import com.google.protobuf.util.Durations;
 import com.google.rpc.Code;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/ServiceYamlParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/ServiceYamlParserTest.java
index 615aacc9b0..de432646fa 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/ServiceYamlParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/ServiceYamlParserTest.java
@@ -14,8 +14,8 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/SourceCodeInfoParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/SourceCodeInfoParserTest.java
index a33f20c782..4be6c37fe4 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/SourceCodeInfoParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/SourceCodeInfoParserTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.gapic.protoparser;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.gapic.model.SourceCodeInfoLocation;
 import com.google.protobuf.DescriptorProtos.FileDescriptorProto;
diff --git a/src/test/java/com/google/api/generator/gapic/protoparser/TypeParserTest.java b/src/test/java/com/google/api/generator/gapic/protoparser/TypeParserTest.java
index 096302e2c1..a79460e915 100644
--- a/src/test/java/com/google/api/generator/gapic/protoparser/TypeParserTest.java
+++ b/src/test/java/com/google/api/generator/gapic/protoparser/TypeParserTest.java
@@ -14,7 +14,7 @@
 
 package com.google.api.generator.gapic.protoparser;
 
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import com.google.api.generator.engine.ast.Reference;
 import com.google.protobuf.Descriptors.Descriptor;
@@ -26,7 +26,6 @@
 import org.junit.Test;
 
 public class TypeParserTest {
-  private static final String ECHO_PACKAGE = "com.google.showcase.v1beta1";
   // TODO(miraleung): Backfill with more tests (e.g. field, message, methods) for Parser.java.
   @Test
   public void parseMessageType_basic() {
diff --git a/src/test/java/com/google/api/generator/gapic/testdata/BUILD.bazel b/src/test/java/com/google/api/generator/gapic/testdata/BUILD.bazel
index 3be657ef66..1a5133b74c 100644
--- a/src/test/java/com/google/api/generator/gapic/testdata/BUILD.bazel
+++ b/src/test/java/com/google/api/generator/gapic/testdata/BUILD.bazel
@@ -33,9 +33,20 @@ genrule(
     ],
 )
 
+proto_library(
+    name = "bookshop_proto",
+    srcs = ["bookshop.proto"],
+    deps = [
+        "@com_google_googleapis//google/api:annotations_proto",
+        "@com_google_googleapis//google/api:client_proto",
+        "@com_google_googleapis//google/api:field_behavior_proto",
+    ],
+)
+
 proto_library(
     name = "showcase_proto",
     srcs = [
+        "compliance.proto",
         "echo.proto",
         "identity.proto",
         "testing.proto",
@@ -100,6 +111,11 @@ java_proto_library(
     deps = [":deprecated_service_proto"],
 )
 
+java_proto_library(
+    name = "bookshop_java_proto",
+    deps = [":bookshop_proto"],
+)
+
 java_proto_library(
     name = "showcase_java_proto",
     deps = [":showcase_proto"],
diff --git a/src/test/java/com/google/api/generator/gapic/testdata/bookshop.proto b/src/test/java/com/google/api/generator/gapic/testdata/bookshop.proto
new file mode 100644
index 0000000000..0498b45430
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/testdata/bookshop.proto
@@ -0,0 +1,61 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+import "google/api/annotations.proto";
+import "google/api/client.proto";
+import "google/api/field_behavior.proto";
+
+package google.bookshop.v1beta1;
+
+option go_package = "github.com/googleapis/gapic-showcase/server/genproto";
+option java_package = "com.google.bookshop.v1beta1";
+option java_outer_classname = "BookshopProto";
+option java_multiple_files = true;
+
+// Exercises name conflict behavior in Java.
+service Bookshop {
+  // This service is meant to only run locally on the port 7469 (keypad digits
+  // for "book").
+  option (google.api.default_host) = "localhost:2665";
+  option (google.api.oauth_scopes) =
+      "https://www.googleapis.com/auth/cloud-platform";
+
+  // This method simply echos the request. This method is showcases unary rpcs.
+  rpc GetBook(GetBookRequest) returns (Book) {
+    option (google.api.http) = {
+      post: "/v1beta1/echo:echo"
+      body: "*"
+    };
+    option (google.api.method_signature) = "books_count,books";
+    option (google.api.method_signature) = "books_list,books";
+  }
+}
+
+message GetBookRequest {
+  // The number of books.
+  int32 books_count = 1;
+
+  // The name of the book list.
+  string books_list = 2;
+
+  // The books.
+  repeated Book books = 3;
+}
+
+message Book {
+  // The bookk title.
+  string title = 1;
+}
diff --git a/src/test/java/com/google/api/generator/gapic/testdata/bookshop_grpc_service_config.json b/src/test/java/com/google/api/generator/gapic/testdata/bookshop_grpc_service_config.json
new file mode 100644
index 0000000000..4604425cb0
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/testdata/bookshop_grpc_service_config.json
@@ -0,0 +1,8 @@
+{
+  "methodConfig": [
+    {
+      "name": [{"service": "google.bookshop.v1beta1.Bookshop"}],
+      "timeout": "60s"
+    }
+  ]
+}
diff --git a/src/test/java/com/google/api/generator/gapic/testdata/compliance.proto b/src/test/java/com/google/api/generator/gapic/testdata/compliance.proto
new file mode 100644
index 0000000000..c602452b13
--- /dev/null
+++ b/src/test/java/com/google/api/generator/gapic/testdata/compliance.proto
@@ -0,0 +1,193 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+import "google/api/annotations.proto";
+import "google/api/client.proto";
+
+package google.showcase.v1beta1;
+
+option go_package = "github.com/googleapis/gapic-showcase/server/genproto";
+option java_package = "com.google.showcase.v1beta1";
+option java_multiple_files = true;
+
+// This service is used to test that GAPICs can transcode proto3 requests to
+// REST format correctly for various types of HTTP annotations.
+service Compliance {
+  // This service is meant to only run locally on the port 7469 (keypad digits
+  // for "show").
+  option (google.api.default_host) = "localhost:7469";
+
+  // This method echoes the ComplianceData request. This method exercises
+  // sending the entire request object in the REST body.
+  rpc RepeatDataBody(RepeatRequest) returns (RepeatResponse) {
+    option (google.api.http) = {
+      post: "/v1beta1/repeat:body"
+      body: "*"
+    };
+  }
+
+  // This method echoes the ComplianceData request. This method exercises
+  // sending the a message-type field in the REST body. Per AIP-127, only
+  // top-level, non-repeated fields can be sent this way.
+  rpc RepeatDataBodyInfo(RepeatRequest) returns (RepeatResponse) {
+    option (google.api.http) = {
+      post: "/v1beta1/repeat:bodyinfo"
+      body: "info"
+    };
+  }
+
+  // This method echoes the ComplianceData request. This method exercises
+  // sending all request fields as query parameters.
+  rpc RepeatDataQuery(RepeatRequest) returns (RepeatResponse) {
+    option (google.api.http) = {
+      get: "/v1beta1/repeat:query"
+    };
+  }
+
+  // This method echoes the ComplianceData request. This method exercises
+  // sending some parameters as "simple" path variables (i.e., of the form
+  // "/bar/{foo}" rather than "/{foo=bar/*}"), and the rest as query parameters.
+  rpc RepeatDataSimplePath(RepeatRequest) returns (RepeatResponse) {
+    option (google.api.http) = {
+      get: "/v1beta1/repeat/{info.f_string}/{info.f_int32}/{info.f_double}/{info.f_bool}/{info.f_kingdom}:simplepath"
+    };
+  }
+
+  // Same as RepeatDataSimplePath, but with a path resource.
+  rpc RepeatDataPathResource(RepeatRequest) returns (RepeatResponse) {
+    option (google.api.http) = {
+      get: "/v1beta1/repeat/{info.f_string=first/*}/{info.f_child.f_string=second/*}/bool/{info.f_bool}:pathresource"
+    };
+  }
+
+  // Same as RepeatDataSimplePath, but with a trailing resource.
+  rpc RepeatDataPathTrailingResource(RepeatRequest) returns (RepeatResponse) {
+    option (google.api.http) = {
+      get: "/v1beta1/repeat/{info.f_string=first/*}/{info.f_child.f_string=second/**}:pathtrailingresource"
+    };
+  }
+}
+
+message RepeatRequest {
+  string name = 1;
+  ComplianceData info = 2;
+
+  // If true, the server will verify that the received request matches
+  // the request with the same name in the compliance test suite.
+  bool server_verify = 3;
+}
+
+message RepeatResponse {
+  ComplianceData info = 1;
+}
+
+// ComplianceSuite contains a set of requests that microgenerators should issue
+// over REST to the Compliance service to test their gRPC-to-REST transcoding
+// implementation.
+message ComplianceSuite {
+  repeated ComplianceGroup group = 1;
+}
+
+// ComplianceGroups encapsulates a group of RPC requests to the Compliance
+// server: one request for each combination of elements of `rpcs` and of
+// `requests`.
+message ComplianceGroup {
+  string name = 1;
+  repeated string rpcs = 2;
+  repeated RepeatRequest requests = 3;
+}
+
+// ComplianceData is a message used for testing REST transcoding of
+// different data types.
+message ComplianceData {
+  enum LifeKingdom {
+    LIFE_KINGDOM_UNSPECIFIED = 0;
+    ARCHAEBACTERIA = 1;
+    EUBACTERIA = 2;
+    PROTISTA = 3;
+    FUNGI = 4;
+    PLANTAE = 5;
+    ANIMALIA = 6;
+}
+  // scalar types
+
+  string f_string = 1;
+
+  int32 f_int32 = 2;
+  sint32 f_sint32 = 3;
+  sfixed32 f_sfixed32 = 4;
+
+  uint32 f_uint32 = 5;
+  fixed32 f_fixed32 = 6;
+
+  int64 f_int64 = 7;
+  sint64 f_sint64 = 8;
+  sfixed64 f_sfixed64 = 9;
+
+  uint64 f_uint64 = 10;
+  fixed64 f_fixed64 = 11;
+
+  double f_double = 12;
+  float f_float = 13;
+
+  optional bool f_bool = 14;
+
+  bytes f_bytes = 15;
+
+  LifeKingdom f_kingdom = 22;
+
+  ComplianceDataChild f_child = 16;
+
+  // optional fields
+
+  optional string p_string = 17;
+  optional int32 p_int32 = 18;
+  optional double p_double = 19;
+  optional bool p_bool = 20;
+  optional LifeKingdom p_kingdom = 23;
+  optional ComplianceDataChild p_child = 21;
+}
+
+message ComplianceDataChild {
+  string f_string = 1;
+  float f_float = 2;
+  double f_double = 3;
+  bool f_bool = 4;
+  Continent f_continent = 11;
+  ComplianceDataGrandchild f_child = 5;
+
+  optional string p_string = 6;
+  optional float p_float = 7;
+  optional double p_double = 8;
+  optional bool p_bool = 9;
+  Continent p_continent = 12;
+  optional ComplianceDataGrandchild p_child = 10;
+}
+
+message ComplianceDataGrandchild {
+  string f_string = 1;
+  double f_double = 2;
+  bool f_bool = 3;
+}
+
+enum Continent {
+  CONTINENT_UNSPECIFIED = 0;
+  AFRICA = 1;
+  AMERICA = 2;
+  ANTARTICA = 3;
+  AUSTRALIA = 4;
+  EUROPE = 5;
+}
\ No newline at end of file
diff --git a/src/test/java/com/google/api/generator/gapic/testdata/echo.proto b/src/test/java/com/google/api/generator/gapic/testdata/echo.proto
index 136ee598f8..ea262faf32 100644
--- a/src/test/java/com/google/api/generator/gapic/testdata/echo.proto
+++ b/src/test/java/com/google/api/generator/gapic/testdata/echo.proto
@@ -130,6 +130,15 @@ service Echo {
       body: "*"
     };
   };
+
+  // This method primarily tests Java name collisions by using the Object
+  // message.
+  rpc CollideName(EchoRequest) returns (Object) {
+    option (google.api.http) = {
+      post: "/v1beta1/echo:foo"
+      body: "*"
+    };
+  }
 }
 
 // A severity enum used to test enum capabilities in GAPIC surfaces
@@ -193,6 +202,12 @@ message EchoResponse {
   Severity severity = 2;
 }
 
+// Tests name collisions with java.lang.Object.
+message Object {
+  // The content specified in the request.
+  string content = 1;
+}
+
 // The request message for the Expand method.
 message ExpandRequest {
   // The content that will be split into words and returned on the stream.
diff --git a/src/test/java/com/google/api/generator/gapic/utils/JavaStyleTest.java b/src/test/java/com/google/api/generator/gapic/utils/JavaStyleTest.java
index 10b65c9b9c..3cf7d647cc 100644
--- a/src/test/java/com/google/api/generator/gapic/utils/JavaStyleTest.java
+++ b/src/test/java/com/google/api/generator/gapic/utils/JavaStyleTest.java
@@ -15,7 +15,7 @@
 package com.google.api.generator.gapic.utils;
 
 import static com.google.common.truth.Truth.assertThat;
-import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
 
diff --git a/src/test/java/com/google/api/generator/test/framework/SingleJUnitTestRunner.java b/src/test/java/com/google/api/generator/test/framework/SingleJUnitTestRunner.java
index a11ad6437a..eda4ae7f8c 100644
--- a/src/test/java/com/google/api/generator/test/framework/SingleJUnitTestRunner.java
+++ b/src/test/java/com/google/api/generator/test/framework/SingleJUnitTestRunner.java
@@ -28,7 +28,7 @@ public static void main(String... args) {
       throw new MissingRequiredArgException("Missing the JUnit class name argument.");
     }
     String className = args[0];
-    Class clazz = null;
+    Class<?> clazz = null;
     try {
       clazz = Class.forName(className);
     } catch (ClassNotFoundException e) {
diff --git a/src/test/java/com/google/api/generator/test/framework/Utils.java b/src/test/java/com/google/api/generator/test/framework/Utils.java
index 728be5f5b5..d38142a582 100644
--- a/src/test/java/com/google/api/generator/test/framework/Utils.java
+++ b/src/test/java/com/google/api/generator/test/framework/Utils.java
@@ -33,7 +33,7 @@ public class Utils {
    * @param fileName the name of saved file, usually it is test method name with suffix `.golden`.
    * @param codegen the generated code from JUnit test.
    */
-  public static void saveCodegenToFile(Class clazz, String fileName, String codegen) {
+  public static void saveCodegenToFile(Class<?> clazz, String fileName, String codegen) {
     // This system environment variable `TEST_OUTPUT_HOME` is used to specify a folder
     // which contains generated output from JUnit test.
     // It will be set when running `bazel run testTarget_update` command.
@@ -51,15 +51,15 @@ public static void saveCodegenToFile(Class clazz, String fileName, String codege
     }
   }
 
-  private static String getTestoutGoldenDir(Class clazz) {
+  private static String getTestoutGoldenDir(Class<?> clazz) {
     return clazz.getPackage().getName().replace(".", "/") + "/goldens/";
   }
 
-  public static String getGoldenDir(Class clazz) {
+  public static String getGoldenDir(Class<?> clazz) {
     return "src/test/java/" + clazz.getPackage().getName().replace(".", "/") + "/goldens/";
   }
 
-  public static String getClassName(Class clazz) {
+  public static String getClassName(Class<?> clazz) {
     return clazz.getSimpleName();
   }
 
diff --git a/src/test/java/com/google/api/generator/util/TrieTest.java b/src/test/java/com/google/api/generator/util/TrieTest.java
index 8854ff7a2f..8769e522cb 100644
--- a/src/test/java/com/google/api/generator/util/TrieTest.java
+++ b/src/test/java/com/google/api/generator/util/TrieTest.java
@@ -14,9 +14,9 @@
 
 package com.google.api.generator.util;
 
-import static junit.framework.Assert.assertEquals;
-import static junit.framework.Assert.assertFalse;
-import static junit.framework.Assert.assertTrue;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.testutils.LineFormatter;
 import java.util.Arrays;
@@ -69,7 +69,6 @@ public void insertAndSearch_multiStringTrie() {
   @Test
   public void dfsTraverseAndReduce_emptyTrie() {
     // Add up points in the tree, where each parent gets (num child node points) * 2 + 1.
-    int baseValue = 0;
     Function<String, Integer> parentPreprocFn = nodeVal -> new Integer(0);
     BiFunction<String, Integer, Integer> leafReduceFn =
         (nodeVal, accVal) -> new Integer(accVal + 1);
@@ -84,7 +83,6 @@ public void dfsTraverseAndReduce_emptyTrie() {
   @Test
   public void dfsTraverseAndReduce_singleNodeTrie() {
     // Add up points in the tree, where each parent gets (num child node points) * 2 + 1.
-    int baseValue = 0;
     Function<String, Integer> parentPreprocFn = nodeVal -> new Integer(0);
     BiFunction<String, Integer, Integer> leafReduceFn =
         (nodeVal, accVal) -> new Integer(accVal + 1);
diff --git a/test/integration/BUILD.bazel b/test/integration/BUILD.bazel
index 23360e672b..addd91b3e8 100644
--- a/test/integration/BUILD.bazel
+++ b/test/integration/BUILD.bazel
@@ -1,12 +1,14 @@
 load(
-    "@com_google_googleapis_imports//:imports.bzl",
-    "java_gapic_assembly_gradle_pkg",
+    "@gapic_generator_java//rules_java_gapic:java_gapic.bzl",
     "java_gapic_library",
     "java_gapic_test",
-    "java_grpc_library",
-    "java_proto_library",
-    "proto_library_with_info",
 )
+load("@io_grpc_grpc_java//:java_grpc_library.bzl", "java_grpc_library")
+load(
+    "@gapic_generator_java//rules_java_gapic:java_gapic_pkg.bzl",
+    "java_gapic_assembly_gradle_pkg",
+)
+load("@rules_gapic//:gapic.bzl", "proto_library_with_info")
 load(
     "//:rules_bazel/java/integration_test.bzl",
     "golden_update",
@@ -28,7 +30,9 @@ INTEGRATION_TEST_LIBRARIES = [
     "pubsub",  # Special=case handling for "_deleted-topic_" resource name patterns.
     "logging",  # Java package remapping in gapic.yaml.
     "redis",  # Has a gapic.yaml.
+    "storage",  # Exercises storage-specific edge cases.
     "library",  # No gRPC service config.
+    "compute",  # REGAPIC test.
 ]
 
 # Keys must match the values in INTEGRATION_TEST_LIBRARIES above.
@@ -40,7 +44,9 @@ API_GAPIC_TARGETS = {
     "pubsub": ":pubsub_java_gapic",
     "logging": "@com_google_googleapis//google/logging/v2:logging_java_gapic",
     "redis": "@com_google_googleapis//google/cloud/redis/v1beta1:redis_java_gapic",
+    "storage": "@com_google_googleapis//google/storage/v2:storage_java_gapic",
     "library": "@com_google_googleapis//google/example/library/v1:library_java_gapic",
+    "compute": "@com_google_googleapis_discovery//google/cloud/compute/v1:compute_small_java_gapic",
 }
 
 [integration_test(
@@ -58,9 +64,6 @@ API_GAPIC_TARGETS = {
 ####################################################
 # API Library Rules
 ####################################################
-# These will eventually go away once more APIs in googleapis have been migrated to the
-# microgenerator.
-
 # Asset API.
 java_gapic_test(
     name = "asset_java_gapic_test_suite",
@@ -99,6 +102,25 @@ java_gapic_assembly_gradle_pkg(
     ],
 )
 
+# Storage API.
+java_gapic_test(
+    name = "storage_java_gapic_test_suite",
+    test_classes = [
+        "com.google.storage.v2.StorageClientTest",
+    ],
+    runtime_deps = ["@com_google_googleapis//google/storage/v2:storage_java_gapic_test"],
+)
+
+java_gapic_assembly_gradle_pkg(
+    name = "google-cloud-storage-v2-java",
+    deps = [
+        "@com_google_googleapis//google/storage/v2:storage_java_gapic",
+        "@com_google_googleapis//google/storage/v2:storage_java_grpc",
+        "@com_google_googleapis//google/storage/v2:storage_java_proto",
+        "@com_google_googleapis//google/storage/v2:storage_proto",
+    ],
+)
+
 # Logging API
 java_gapic_test(
     name = "logging_java_gapic_test_suite",
@@ -278,7 +300,6 @@ java_gapic_assembly_gradle_pkg(
 )
 
 # PubSub
-# TODO: Remove some of these targets when PubSub has been migrated in googleapis.
 java_gapic_library(
     name = "pubsub_java_gapic",
     srcs = ["@com_google_googleapis//google/pubsub/v1:pubsub_proto_with_info"],
diff --git a/test/integration/apis/kms/v1/cloudkms_test_mixins_v1.yaml b/test/integration/apis/kms/v1/cloudkms_test_mixins_v1.yaml
index 2828ca13f0..7ce51316c7 100644
--- a/test/integration/apis/kms/v1/cloudkms_test_mixins_v1.yaml
+++ b/test/integration/apis/kms/v1/cloudkms_test_mixins_v1.yaml
@@ -16,12 +16,14 @@ documentation:
     Manages keys and performs cryptographic operations in a central cloud
     service, for direct use by other cloud resources and applications.
   rules:
+  # This RPC shouldn't appear in the proto, since it's been clobered by KMS's definition in the proto.
   - selector: google.iam.v1.IAMPolicy.GetIamPolicy
     description: |-
       Gets the access control policy for a resource. Returns an empty policy
       if the resource exists and does not have a policy set.
 
-  # This RPC shouldn't appear in the proto even though the documentation field is set.
+  # This RPC shouldn't appear in the proto, since it's not in the HTTP rules list below,
+  # even though the documentation field is set.
   - selector: google.iam.v1.IAMPolicy.SetIamPolicy
     description: |-
       Sets the access control policy on the specified resource. Replaces
diff --git a/test/integration/goldens/asset/BUILD.bazel b/test/integration/goldens/asset/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/asset/BUILD.bazel
+++ b/test/integration/goldens/asset/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClient.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClient.java
index f1bbf06c9f..1860b0cca4 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClient.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.asset.v1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -28,6 +27,7 @@
 import com.google.api.gax.rpc.OperationCallable;
 import com.google.api.gax.rpc.PageContext;
 import com.google.api.gax.rpc.UnaryCallable;
+import com.google.api.resourcenames.ResourceName;
 import com.google.cloud.asset.v1.stub.AssetServiceStub;
 import com.google.cloud.asset.v1.stub.AssetServiceStubSettings;
 import com.google.common.util.concurrent.MoreExecutors;
@@ -271,6 +271,154 @@ public final UnaryCallable<ExportAssetsRequest, Operation> exportAssetsCallable(
     return stub.exportAssetsCallable();
   }
 
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Lists assets with time and resource types and returns paged results in response.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
+   *   ResourceName parent = FeedName.ofProjectFeedName("[PROJECT]", "[FEED]");
+   *   for (Asset element : assetServiceClient.listAssets(parent).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param parent Required. Name of the organization or project the assets belong to. Format:
+   *     "organizations/[organization-number]" (such as "organizations/123"),
+   *     "projects/[project-id]" (such as "projects/my-project-id"), or "projects/[project-number]"
+   *     (such as "projects/12345").
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final ListAssetsPagedResponse listAssets(ResourceName parent) {
+    ListAssetsRequest request =
+        ListAssetsRequest.newBuilder().setParent(parent == null ? null : parent.toString()).build();
+    return listAssets(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Lists assets with time and resource types and returns paged results in response.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
+   *   String parent = FeedName.ofProjectFeedName("[PROJECT]", "[FEED]").toString();
+   *   for (Asset element : assetServiceClient.listAssets(parent).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param parent Required. Name of the organization or project the assets belong to. Format:
+   *     "organizations/[organization-number]" (such as "organizations/123"),
+   *     "projects/[project-id]" (such as "projects/my-project-id"), or "projects/[project-number]"
+   *     (such as "projects/12345").
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final ListAssetsPagedResponse listAssets(String parent) {
+    ListAssetsRequest request = ListAssetsRequest.newBuilder().setParent(parent).build();
+    return listAssets(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Lists assets with time and resource types and returns paged results in response.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
+   *   ListAssetsRequest request =
+   *       ListAssetsRequest.newBuilder()
+   *           .setParent(FeedName.ofProjectFeedName("[PROJECT]", "[FEED]").toString())
+   *           .setReadTime(Timestamp.newBuilder().build())
+   *           .addAllAssetTypes(new ArrayList<String>())
+   *           .setContentType(ContentType.forNumber(0))
+   *           .setPageSize(883849137)
+   *           .setPageToken("pageToken873572522")
+   *           .build();
+   *   for (Asset element : assetServiceClient.listAssets(request).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final ListAssetsPagedResponse listAssets(ListAssetsRequest request) {
+    return listAssetsPagedCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Lists assets with time and resource types and returns paged results in response.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
+   *   ListAssetsRequest request =
+   *       ListAssetsRequest.newBuilder()
+   *           .setParent(FeedName.ofProjectFeedName("[PROJECT]", "[FEED]").toString())
+   *           .setReadTime(Timestamp.newBuilder().build())
+   *           .addAllAssetTypes(new ArrayList<String>())
+   *           .setContentType(ContentType.forNumber(0))
+   *           .setPageSize(883849137)
+   *           .setPageToken("pageToken873572522")
+   *           .build();
+   *   ApiFuture<Asset> future = assetServiceClient.listAssetsPagedCallable().futureCall(request);
+   *   // Do something.
+   *   for (Asset element : future.get().iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<ListAssetsRequest, ListAssetsPagedResponse> listAssetsPagedCallable() {
+    return stub.listAssetsPagedCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Lists assets with time and resource types and returns paged results in response.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
+   *   ListAssetsRequest request =
+   *       ListAssetsRequest.newBuilder()
+   *           .setParent(FeedName.ofProjectFeedName("[PROJECT]", "[FEED]").toString())
+   *           .setReadTime(Timestamp.newBuilder().build())
+   *           .addAllAssetTypes(new ArrayList<String>())
+   *           .setContentType(ContentType.forNumber(0))
+   *           .setPageSize(883849137)
+   *           .setPageToken("pageToken873572522")
+   *           .build();
+   *   while (true) {
+   *     ListAssetsResponse response = assetServiceClient.listAssetsCallable().call(request);
+   *     for (Asset element : response.getResponsesList()) {
+   *       // doThingsWith(element);
+   *     }
+   *     String nextPageToken = response.getNextPageToken();
+   *     if (!Strings.isNullOrEmpty(nextPageToken)) {
+   *       request = request.toBuilder().setPageToken(nextPageToken).build();
+   *     } else {
+   *       break;
+   *     }
+   *   }
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<ListAssetsRequest, ListAssetsResponse> listAssetsCallable() {
+    return stub.listAssetsCallable();
+  }
+
   // AUTO-GENERATED DOCUMENTATION AND METHOD.
   /**
    * Batch gets the update history of assets that overlap a time window. For IAM_POLICY content,
@@ -747,7 +895,7 @@ public final UnaryCallable<DeleteFeedRequest, Empty> deleteFeedCallable() {
    *
    * @param scope Required. A scope can be a project, a folder, or an organization. The search is
    *     limited to the resources within the `scope`. The caller must be granted the
-   *     [`cloudasset.assets.searchAllResources`](http://cloud.google.com/asset-inventory/docs/access-control#required_permissions)
+   *     [`cloudasset.assets.searchAllResources`](https://cloud.google.com/asset-inventory/docs/access-control#required_permissions)
    *     permission on the desired scope.
    *     <p>The allowed values are:
    *     <ul>
@@ -758,32 +906,36 @@ public final UnaryCallable<DeleteFeedRequest, Empty> deleteFeedCallable() {
    *     </ul>
    *
    * @param query Optional. The query statement. See [how to construct a
-   *     query](http://cloud.google.com/asset-inventory/docs/searching-resources#how_to_construct_a_query)
+   *     query](https://cloud.google.com/asset-inventory/docs/searching-resources#how_to_construct_a_query)
    *     for more information. If not specified or empty, it will search all the resources within
-   *     the specified `scope`. Note that the query string is compared against each Cloud IAM policy
-   *     binding, including its members, roles, and Cloud IAM conditions. The returned Cloud IAM
-   *     policies will only contain the bindings that match your query. To learn more about the IAM
-   *     policy structure, see [IAM policy
-   *     doc](https://cloud.google.com/iam/docs/policies#structure).
+   *     the specified `scope`.
    *     <p>Examples:
    *     <ul>
    *       <li>`name:Important` to find Cloud resources whose name contains "Important" as a word.
+   *       <li>`name=Important` to find the Cloud resource whose name is exactly "Important".
    *       <li>`displayName:Impor&#42;` to find Cloud resources whose display name contains "Impor"
-   *           as a prefix.
-   *       <li>`description:&#42;por&#42;` to find Cloud resources whose description contains "por"
-   *           as a substring.
-   *       <li>`location:us-west&#42;` to find Cloud resources whose location is prefixed with
-   *           "us-west".
+   *           as a prefix of any word in the field.
+   *       <li>`location:us-west&#42;` to find Cloud resources whose location contains both "us" and
+   *           "west" as prefixes.
    *       <li>`labels:prod` to find Cloud resources whose labels contain "prod" as a key or value.
    *       <li>`labels.env:prod` to find Cloud resources that have a label "env" and its value is
    *           "prod".
    *       <li>`labels.env:&#42;` to find Cloud resources that have a label "env".
+   *       <li>`kmsKey:key` to find Cloud resources encrypted with a customer-managed encryption key
+   *           whose name contains the word "key".
+   *       <li>`state:ACTIVE` to find Cloud resources whose state contains "ACTIVE" as a word.
+   *       <li>`NOT state:ACTIVE` to find {{gcp_name}} resources whose state doesn't contain
+   *           "ACTIVE" as a word.
+   *       <li>`createTime&lt;1609459200` to find Cloud resources that were created before
+   *           "2021-01-01 00:00:00 UTC". 1609459200 is the epoch timestamp of "2021-01-01 00:00:00
+   *           UTC" in seconds.
+   *       <li>`updateTime&gt;1609459200` to find Cloud resources that were updated after
+   *           "2021-01-01 00:00:00 UTC". 1609459200 is the epoch timestamp of "2021-01-01 00:00:00
+   *           UTC" in seconds.
    *       <li>`Important` to find Cloud resources that contain "Important" as a word in any of the
    *           searchable fields.
-   *       <li>`Impor&#42;` to find Cloud resources that contain "Impor" as a prefix in any of the
-   *           searchable fields.
-   *       <li>`&#42;por&#42;` to find Cloud resources that contain "por" as a substring in any of
-   *           the searchable fields.
+   *       <li>`Impor&#42;` to find Cloud resources that contain "Impor" as a prefix of any word in
+   *           any of the searchable fields.
    *       <li>`Important location:(us-west1 OR global)` to find Cloud resources that contain
    *           "Important" as a word in any of the searchable fields and are also located in the
    *           "us-west1" region or the "global" location.
@@ -792,6 +944,16 @@ public final UnaryCallable<DeleteFeedRequest, Empty> deleteFeedCallable() {
    * @param assetTypes Optional. A list of asset types that this request searches for. If empty, it
    *     will search all the [searchable asset
    *     types](https://cloud.google.com/asset-inventory/docs/supported-asset-types#searchable_asset_types).
+   *     <p>Regular expressions are also supported. For example:
+   *     <ul>
+   *       <li>"compute.googleapis.com.&#42;" snapshots resources whose asset type starts with
+   *           "compute.googleapis.com".
+   *       <li>".&#42;Instance" snapshots resources whose asset type ends with "Instance".
+   *       <li>".&#42;Instance.&#42;" snapshots resources whose asset type contains "Instance".
+   *     </ul>
+   *     <p>See [RE2](https://github.com/google/re2/wiki/Syntax) for all supported regular
+   *     expression syntax. If the regular expression does not match any supported asset type, an
+   *     INVALID_ARGUMENT error will be returned.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
   public final SearchAllResourcesPagedResponse searchAllResources(
@@ -933,7 +1095,7 @@ public final SearchAllResourcesPagedResponse searchAllResources(
    *
    * @param scope Required. A scope can be a project, a folder, or an organization. The search is
    *     limited to the IAM policies within the `scope`. The caller must be granted the
-   *     [`cloudasset.assets.searchAllIamPolicies`](http://cloud.google.com/asset-inventory/docs/access-control#required_permissions)
+   *     [`cloudasset.assets.searchAllIamPolicies`](https://cloud.google.com/asset-inventory/docs/access-control#required_permissions)
    *     permission on the desired scope.
    *     <p>The allowed values are:
    *     <ul>
@@ -946,25 +1108,38 @@ public final SearchAllResourcesPagedResponse searchAllResources(
    * @param query Optional. The query statement. See [how to construct a
    *     query](https://cloud.google.com/asset-inventory/docs/searching-iam-policies#how_to_construct_a_query)
    *     for more information. If not specified or empty, it will search all the IAM policies within
-   *     the specified `scope`.
+   *     the specified `scope`. Note that the query string is compared against each Cloud IAM policy
+   *     binding, including its members, roles, and Cloud IAM conditions. The returned Cloud IAM
+   *     policies will only contain the bindings that match your query. To learn more about the IAM
+   *     policy structure, see [IAM policy
+   *     doc](https://cloud.google.com/iam/docs/policies#structure).
    *     <p>Examples:
    *     <ul>
    *       <li>`policy:amy{@literal @}gmail.com` to find IAM policy bindings that specify user
    *           "amy{@literal @}gmail.com".
    *       <li>`policy:roles/compute.admin` to find IAM policy bindings that specify the Compute
    *           Admin role.
+   *       <li>`policy:comp&#42;` to find IAM policy bindings that contain "comp" as a prefix of any
+   *           word in the binding.
    *       <li>`policy.role.permissions:storage.buckets.update` to find IAM policy bindings that
    *           specify a role containing "storage.buckets.update" permission. Note that if callers
    *           don't have `iam.roles.get` access to a role's included permissions, policy bindings
    *           that specify this role will be dropped from the search results.
+   *       <li>`policy.role.permissions:upd&#42;` to find IAM policy bindings that specify a role
+   *           containing "upd" as a prefix of any word in the role permission. Note that if callers
+   *           don't have `iam.roles.get` access to a role's included permissions, policy bindings
+   *           that specify this role will be dropped from the search results.
    *       <li>`resource:organizations/123456` to find IAM policy bindings that are set on
    *           "organizations/123456".
+   *       <li>`resource=//cloudresourcemanager.googleapis.com/projects/myproject` to find IAM
+   *           policy bindings that are set on the project named "myproject".
    *       <li>`Important` to find IAM policy bindings that contain "Important" as a word in any of
    *           the searchable fields (except for the included permissions).
-   *       <li>`&#42;por&#42;` to find IAM policy bindings that contain "por" as a substring in any
-   *           of the searchable fields (except for the included permissions).
    *       <li>`resource:(instance1 OR instance2) policy:amy` to find IAM policy bindings that are
    *           set on resources "instance1" or "instance2" and also specify user "amy".
+   *       <li>`roles:roles/compute.admin` to find IAM policy bindings that specify the Compute
+   *           Admin role.
+   *       <li>`memberTypes:user` to find IAM policy bindings that contain the "user" member type.
    *     </ul>
    *
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
@@ -991,6 +1166,8 @@ public final SearchAllIamPoliciesPagedResponse searchAllIamPolicies(String scope
    *           .setQuery("query107944136")
    *           .setPageSize(883849137)
    *           .setPageToken("pageToken873572522")
+   *           .addAllAssetTypes(new ArrayList<String>())
+   *           .setOrderBy("orderBy-1207110587")
    *           .build();
    *   for (IamPolicySearchResult element :
    *       assetServiceClient.searchAllIamPolicies(request).iterateAll()) {
@@ -1023,6 +1200,8 @@ public final SearchAllIamPoliciesPagedResponse searchAllIamPolicies(
    *           .setQuery("query107944136")
    *           .setPageSize(883849137)
    *           .setPageToken("pageToken873572522")
+   *           .addAllAssetTypes(new ArrayList<String>())
+   *           .setOrderBy("orderBy-1207110587")
    *           .build();
    *   ApiFuture<IamPolicySearchResult> future =
    *       assetServiceClient.searchAllIamPoliciesPagedCallable().futureCall(request);
@@ -1054,6 +1233,8 @@ public final SearchAllIamPoliciesPagedResponse searchAllIamPolicies(
    *           .setQuery("query107944136")
    *           .setPageSize(883849137)
    *           .setPageToken("pageToken873572522")
+   *           .addAllAssetTypes(new ArrayList<String>())
+   *           .setOrderBy("orderBy-1207110587")
    *           .build();
    *   while (true) {
    *     SearchAllIamPoliciesResponse response =
@@ -1257,6 +1438,79 @@ public boolean awaitTermination(long duration, TimeUnit unit) throws Interrupted
     return stub.awaitTermination(duration, unit);
   }
 
+  public static class ListAssetsPagedResponse
+      extends AbstractPagedListResponse<
+          ListAssetsRequest,
+          ListAssetsResponse,
+          Asset,
+          ListAssetsPage,
+          ListAssetsFixedSizeCollection> {
+
+    public static ApiFuture<ListAssetsPagedResponse> createAsync(
+        PageContext<ListAssetsRequest, ListAssetsResponse, Asset> context,
+        ApiFuture<ListAssetsResponse> futureResponse) {
+      ApiFuture<ListAssetsPage> futurePage =
+          ListAssetsPage.createEmptyPage().createPageAsync(context, futureResponse);
+      return ApiFutures.transform(
+          futurePage, input -> new ListAssetsPagedResponse(input), MoreExecutors.directExecutor());
+    }
+
+    private ListAssetsPagedResponse(ListAssetsPage page) {
+      super(page, ListAssetsFixedSizeCollection.createEmptyCollection());
+    }
+  }
+
+  public static class ListAssetsPage
+      extends AbstractPage<ListAssetsRequest, ListAssetsResponse, Asset, ListAssetsPage> {
+
+    private ListAssetsPage(
+        PageContext<ListAssetsRequest, ListAssetsResponse, Asset> context,
+        ListAssetsResponse response) {
+      super(context, response);
+    }
+
+    private static ListAssetsPage createEmptyPage() {
+      return new ListAssetsPage(null, null);
+    }
+
+    @Override
+    protected ListAssetsPage createPage(
+        PageContext<ListAssetsRequest, ListAssetsResponse, Asset> context,
+        ListAssetsResponse response) {
+      return new ListAssetsPage(context, response);
+    }
+
+    @Override
+    public ApiFuture<ListAssetsPage> createPageAsync(
+        PageContext<ListAssetsRequest, ListAssetsResponse, Asset> context,
+        ApiFuture<ListAssetsResponse> futureResponse) {
+      return super.createPageAsync(context, futureResponse);
+    }
+  }
+
+  public static class ListAssetsFixedSizeCollection
+      extends AbstractFixedSizeCollection<
+          ListAssetsRequest,
+          ListAssetsResponse,
+          Asset,
+          ListAssetsPage,
+          ListAssetsFixedSizeCollection> {
+
+    private ListAssetsFixedSizeCollection(List<ListAssetsPage> pages, int collectionSize) {
+      super(pages, collectionSize);
+    }
+
+    private static ListAssetsFixedSizeCollection createEmptyCollection() {
+      return new ListAssetsFixedSizeCollection(null, 0);
+    }
+
+    @Override
+    protected ListAssetsFixedSizeCollection createCollection(
+        List<ListAssetsPage> pages, int collectionSize) {
+      return new ListAssetsFixedSizeCollection(pages, collectionSize);
+    }
+  }
+
   public static class SearchAllResourcesPagedResponse
       extends AbstractPagedListResponse<
           SearchAllResourcesRequest,
@@ -1273,12 +1527,7 @@ public static ApiFuture<SearchAllResourcesPagedResponse> createAsync(
           SearchAllResourcesPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<SearchAllResourcesPage, SearchAllResourcesPagedResponse>() {
-            @Override
-            public SearchAllResourcesPagedResponse apply(SearchAllResourcesPage input) {
-              return new SearchAllResourcesPagedResponse(input);
-            }
-          },
+          input -> new SearchAllResourcesPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -1363,12 +1612,7 @@ public static ApiFuture<SearchAllIamPoliciesPagedResponse> createAsync(
           SearchAllIamPoliciesPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<SearchAllIamPoliciesPage, SearchAllIamPoliciesPagedResponse>() {
-            @Override
-            public SearchAllIamPoliciesPagedResponse apply(SearchAllIamPoliciesPage input) {
-              return new SearchAllIamPoliciesPagedResponse(input);
-            }
-          },
+          input -> new SearchAllIamPoliciesPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClientTest.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClientTest.java
index e419696424..de8ca67414 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClientTest.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceClientTest.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.asset.v1;
 
+import static com.google.cloud.asset.v1.AssetServiceClient.ListAssetsPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllIamPoliciesPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllResourcesPagedResponse;
 
@@ -27,6 +28,7 @@
 import com.google.api.gax.rpc.ApiClientHeaderProvider;
 import com.google.api.gax.rpc.InvalidArgumentException;
 import com.google.api.gax.rpc.StatusCode;
+import com.google.api.resourcenames.ResourceName;
 import com.google.common.collect.Lists;
 import com.google.longrunning.Operation;
 import com.google.protobuf.AbstractMessage;
@@ -52,10 +54,10 @@
 
 @Generated("by gapic-generator-java")
 public class AssetServiceClientTest {
+  private static MockAssetService mockAssetService;
   private static MockServiceHelper mockServiceHelper;
-  private AssetServiceClient client;
   private LocalChannelProvider channelProvider;
-  private static MockAssetService mockAssetService;
+  private AssetServiceClient client;
 
   @BeforeClass
   public static void startStaticServer() {
@@ -154,6 +156,94 @@ public void exportAssetsExceptionTest() throws Exception {
     }
   }
 
+  @Test
+  public void listAssetsTest() throws Exception {
+    Asset responsesElement = Asset.newBuilder().build();
+    ListAssetsResponse expectedResponse =
+        ListAssetsResponse.newBuilder()
+            .setNextPageToken("")
+            .addAllAssets(Arrays.asList(responsesElement))
+            .build();
+    mockAssetService.addResponse(expectedResponse);
+
+    ResourceName parent = FeedName.ofProjectFeedName("[PROJECT]", "[FEED]");
+
+    ListAssetsPagedResponse pagedListResponse = client.listAssets(parent);
+
+    List<Asset> resources = Lists.newArrayList(pagedListResponse.iterateAll());
+
+    Assert.assertEquals(1, resources.size());
+    Assert.assertEquals(expectedResponse.getAssetsList().get(0), resources.get(0));
+
+    List<AbstractMessage> actualRequests = mockAssetService.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    ListAssetsRequest actualRequest = ((ListAssetsRequest) actualRequests.get(0));
+
+    Assert.assertEquals(parent.toString(), actualRequest.getParent());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void listAssetsExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockAssetService.addException(exception);
+
+    try {
+      ResourceName parent = FeedName.ofProjectFeedName("[PROJECT]", "[FEED]");
+      client.listAssets(parent);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void listAssetsTest2() throws Exception {
+    Asset responsesElement = Asset.newBuilder().build();
+    ListAssetsResponse expectedResponse =
+        ListAssetsResponse.newBuilder()
+            .setNextPageToken("")
+            .addAllAssets(Arrays.asList(responsesElement))
+            .build();
+    mockAssetService.addResponse(expectedResponse);
+
+    String parent = "parent-995424086";
+
+    ListAssetsPagedResponse pagedListResponse = client.listAssets(parent);
+
+    List<Asset> resources = Lists.newArrayList(pagedListResponse.iterateAll());
+
+    Assert.assertEquals(1, resources.size());
+    Assert.assertEquals(expectedResponse.getAssetsList().get(0), resources.get(0));
+
+    List<AbstractMessage> actualRequests = mockAssetService.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    ListAssetsRequest actualRequest = ((ListAssetsRequest) actualRequests.get(0));
+
+    Assert.assertEquals(parent, actualRequest.getParent());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void listAssetsExceptionTest2() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockAssetService.addException(exception);
+
+    try {
+      String parent = "parent-995424086";
+      client.listAssets(parent);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
   @Test
   public void batchGetAssetsHistoryTest() throws Exception {
     BatchGetAssetsHistoryResponse expectedResponse =
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceSettings.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceSettings.java
index 50c5dca652..df338c00a9 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceSettings.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/AssetServiceSettings.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.asset.v1;
 
+import static com.google.cloud.asset.v1.AssetServiceClient.ListAssetsPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllIamPoliciesPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllResourcesPagedResponse;
 
@@ -84,6 +85,12 @@ public UnaryCallSettings<ExportAssetsRequest, Operation> exportAssetsSettings()
     return ((AssetServiceStubSettings) getStubSettings()).exportAssetsOperationSettings();
   }
 
+  /** Returns the object with the settings used for calls to listAssets. */
+  public PagedCallSettings<ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+      listAssetsSettings() {
+    return ((AssetServiceStubSettings) getStubSettings()).listAssetsSettings();
+  }
+
   /** Returns the object with the settings used for calls to batchGetAssetsHistory. */
   public UnaryCallSettings<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistorySettings() {
@@ -238,14 +245,13 @@ public AssetServiceStubSettings.Builder getStubSettingsBuilder() {
       return ((AssetServiceStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
@@ -263,6 +269,12 @@ public UnaryCallSettings.Builder<ExportAssetsRequest, Operation> exportAssetsSet
       return getStubSettingsBuilder().exportAssetsOperationSettings();
     }
 
+    /** Returns the builder for the settings used for calls to listAssets. */
+    public PagedCallSettings.Builder<ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+        listAssetsSettings() {
+      return getStubSettingsBuilder().listAssetsSettings();
+    }
+
     /** Returns the builder for the settings used for calls to batchGetAssetsHistory. */
     public UnaryCallSettings.Builder<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
         batchGetAssetsHistorySettings() {
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/FeedName.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/FeedName.java
index d8c9ee9593..8c19eaba01 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/FeedName.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/FeedName.java
@@ -295,8 +295,8 @@ private Builder(FeedName feedName) {
       Preconditions.checkArgument(
           Objects.equals(feedName.pathTemplate, PROJECT_FEED),
           "toBuilder is only supported when FeedName has the pattern of projects/{project}/feeds/{feed}");
-      project = feedName.project;
-      feed = feedName.feed;
+      this.project = feedName.project;
+      this.feed = feedName.feed;
     }
 
     public FeedName build() {
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/MockAssetServiceImpl.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/MockAssetServiceImpl.java
index 27b5f4021b..643691d8d4 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/MockAssetServiceImpl.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/MockAssetServiceImpl.java
@@ -81,6 +81,27 @@ public void exportAssets(
     }
   }
 
+  @Override
+  public void listAssets(
+      ListAssetsRequest request, StreamObserver<ListAssetsResponse> responseObserver) {
+    Object response = responses.poll();
+    if (response instanceof ListAssetsResponse) {
+      requests.add(request);
+      responseObserver.onNext(((ListAssetsResponse) response));
+      responseObserver.onCompleted();
+    } else if (response instanceof Exception) {
+      responseObserver.onError(((Exception) response));
+    } else {
+      responseObserver.onError(
+          new IllegalArgumentException(
+              String.format(
+                  "Unrecognized response type %s for method ListAssets, expected %s or %s",
+                  response == null ? "null" : response.getClass().getName(),
+                  ListAssetsResponse.class.getName(),
+                  Exception.class.getName())));
+    }
+  }
+
   @Override
   public void batchGetAssetsHistory(
       BatchGetAssetsHistoryRequest request,
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/gapic_metadata.json b/test/integration/goldens/asset/com/google/cloud/asset/v1/gapic_metadata.json
index d2c1608bb4..ea1187e7ac 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/gapic_metadata.json
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/gapic_metadata.json
@@ -31,6 +31,9 @@
             "GetFeed": {
               "methods": ["getFeed", "getFeed", "getFeed", "getFeedCallable"]
             },
+            "ListAssets": {
+              "methods": ["listAssets", "listAssets", "listAssets", "listAssetsPagedCallable", "listAssetsCallable"]
+            },
             "ListFeeds": {
               "methods": ["listFeeds", "listFeeds", "listFeedsCallable"]
             },
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/package-info.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/package-info.java
index e4032e3df0..27db247ed3 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/package-info.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/package-info.java
@@ -27,7 +27,7 @@
  * try (AssetServiceClient assetServiceClient = AssetServiceClient.create()) {
  *   BatchGetAssetsHistoryRequest request =
  *       BatchGetAssetsHistoryRequest.newBuilder()
- *           .setParent(ProjectName.of("[PROJECT]").toString())
+ *           .setParent(FeedName.ofProjectFeedName("[PROJECT]", "[FEED]").toString())
  *           .addAllAssetNames(new ArrayList<String>())
  *           .setContentType(ContentType.forNumber(0))
  *           .setReadTimeWindow(TimeWindow.newBuilder().build())
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStub.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStub.java
index b97b1874bb..462d7e2922 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStub.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStub.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.asset.v1.stub;
 
+import static com.google.cloud.asset.v1.AssetServiceClient.ListAssetsPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllIamPoliciesPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllResourcesPagedResponse;
 
@@ -34,6 +35,8 @@
 import com.google.cloud.asset.v1.ExportAssetsResponse;
 import com.google.cloud.asset.v1.Feed;
 import com.google.cloud.asset.v1.GetFeedRequest;
+import com.google.cloud.asset.v1.ListAssetsRequest;
+import com.google.cloud.asset.v1.ListAssetsResponse;
 import com.google.cloud.asset.v1.ListFeedsRequest;
 import com.google.cloud.asset.v1.ListFeedsResponse;
 import com.google.cloud.asset.v1.SearchAllIamPoliciesRequest;
@@ -68,6 +71,14 @@ public UnaryCallable<ExportAssetsRequest, Operation> exportAssetsCallable() {
     throw new UnsupportedOperationException("Not implemented: exportAssetsCallable()");
   }
 
+  public UnaryCallable<ListAssetsRequest, ListAssetsPagedResponse> listAssetsPagedCallable() {
+    throw new UnsupportedOperationException("Not implemented: listAssetsPagedCallable()");
+  }
+
+  public UnaryCallable<ListAssetsRequest, ListAssetsResponse> listAssetsCallable() {
+    throw new UnsupportedOperationException("Not implemented: listAssetsCallable()");
+  }
+
   public UnaryCallable<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistoryCallable() {
     throw new UnsupportedOperationException("Not implemented: batchGetAssetsHistoryCallable()");
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStubSettings.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStubSettings.java
index cceca0029a..24b8b894a1 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStubSettings.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/AssetServiceStubSettings.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.asset.v1.stub;
 
+import static com.google.cloud.asset.v1.AssetServiceClient.ListAssetsPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllIamPoliciesPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllResourcesPagedResponse;
 
@@ -49,6 +50,7 @@
 import com.google.cloud.asset.v1.AnalyzeIamPolicyLongrunningResponse;
 import com.google.cloud.asset.v1.AnalyzeIamPolicyRequest;
 import com.google.cloud.asset.v1.AnalyzeIamPolicyResponse;
+import com.google.cloud.asset.v1.Asset;
 import com.google.cloud.asset.v1.BatchGetAssetsHistoryRequest;
 import com.google.cloud.asset.v1.BatchGetAssetsHistoryResponse;
 import com.google.cloud.asset.v1.CreateFeedRequest;
@@ -58,6 +60,8 @@
 import com.google.cloud.asset.v1.Feed;
 import com.google.cloud.asset.v1.GetFeedRequest;
 import com.google.cloud.asset.v1.IamPolicySearchResult;
+import com.google.cloud.asset.v1.ListAssetsRequest;
+import com.google.cloud.asset.v1.ListAssetsResponse;
 import com.google.cloud.asset.v1.ListFeedsRequest;
 import com.google.cloud.asset.v1.ListFeedsResponse;
 import com.google.cloud.asset.v1.ResourceSearchResult;
@@ -119,6 +123,8 @@ public class AssetServiceStubSettings extends StubSettings<AssetServiceStubSetti
   private final OperationCallSettings<
           ExportAssetsRequest, ExportAssetsResponse, ExportAssetsRequest>
       exportAssetsOperationSettings;
+  private final PagedCallSettings<ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+      listAssetsSettings;
   private final UnaryCallSettings<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistorySettings;
   private final UnaryCallSettings<CreateFeedRequest, Feed> createFeedSettings;
@@ -144,6 +150,42 @@ public class AssetServiceStubSettings extends StubSettings<AssetServiceStubSetti
           AnalyzeIamPolicyLongrunningRequest>
       analyzeIamPolicyLongrunningOperationSettings;
 
+  private static final PagedListDescriptor<ListAssetsRequest, ListAssetsResponse, Asset>
+      LIST_ASSETS_PAGE_STR_DESC =
+          new PagedListDescriptor<ListAssetsRequest, ListAssetsResponse, Asset>() {
+            @Override
+            public String emptyToken() {
+              return "";
+            }
+
+            @Override
+            public ListAssetsRequest injectToken(ListAssetsRequest payload, String token) {
+              return ListAssetsRequest.newBuilder(payload).setPageToken(token).build();
+            }
+
+            @Override
+            public ListAssetsRequest injectPageSize(ListAssetsRequest payload, int pageSize) {
+              return ListAssetsRequest.newBuilder(payload).setPageSize(pageSize).build();
+            }
+
+            @Override
+            public Integer extractPageSize(ListAssetsRequest payload) {
+              return payload.getPageSize();
+            }
+
+            @Override
+            public String extractNextToken(ListAssetsResponse payload) {
+              return payload.getNextPageToken();
+            }
+
+            @Override
+            public Iterable<Asset> extractResources(ListAssetsResponse payload) {
+              return payload.getAssetsList() == null
+                  ? ImmutableList.<Asset>of()
+                  : payload.getAssetsList();
+            }
+          };
+
   private static final PagedListDescriptor<
           SearchAllResourcesRequest, SearchAllResourcesResponse, ResourceSearchResult>
       SEARCH_ALL_RESOURCES_PAGE_STR_DESC =
@@ -226,6 +268,23 @@ public Iterable<IamPolicySearchResult> extractResources(
             }
           };
 
+  private static final PagedListResponseFactory<
+          ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+      LIST_ASSETS_PAGE_STR_FACT =
+          new PagedListResponseFactory<
+              ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>() {
+            @Override
+            public ApiFuture<ListAssetsPagedResponse> getFuturePagedResponse(
+                UnaryCallable<ListAssetsRequest, ListAssetsResponse> callable,
+                ListAssetsRequest request,
+                ApiCallContext context,
+                ApiFuture<ListAssetsResponse> futureResponse) {
+              PageContext<ListAssetsRequest, ListAssetsResponse, Asset> pageContext =
+                  PageContext.create(callable, LIST_ASSETS_PAGE_STR_DESC, request, context);
+              return ListAssetsPagedResponse.createAsync(pageContext, futureResponse);
+            }
+          };
+
   private static final PagedListResponseFactory<
           SearchAllResourcesRequest, SearchAllResourcesResponse, SearchAllResourcesPagedResponse>
       SEARCH_ALL_RESOURCES_PAGE_STR_FACT =
@@ -285,6 +344,12 @@ public UnaryCallSettings<ExportAssetsRequest, Operation> exportAssetsSettings()
     return exportAssetsOperationSettings;
   }
 
+  /** Returns the object with the settings used for calls to listAssets. */
+  public PagedCallSettings<ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+      listAssetsSettings() {
+    return listAssetsSettings;
+  }
+
   /** Returns the object with the settings used for calls to batchGetAssetsHistory. */
   public UnaryCallSettings<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistorySettings() {
@@ -375,6 +440,11 @@ public static String getDefaultEndpoint() {
     return "cloudasset.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "cloudasset.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -382,7 +452,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -424,6 +496,7 @@ protected AssetServiceStubSettings(Builder settingsBuilder) throws IOException {
 
     exportAssetsSettings = settingsBuilder.exportAssetsSettings().build();
     exportAssetsOperationSettings = settingsBuilder.exportAssetsOperationSettings().build();
+    listAssetsSettings = settingsBuilder.listAssetsSettings().build();
     batchGetAssetsHistorySettings = settingsBuilder.batchGetAssetsHistorySettings().build();
     createFeedSettings = settingsBuilder.createFeedSettings().build();
     getFeedSettings = settingsBuilder.getFeedSettings().build();
@@ -446,6 +519,9 @@ public static class Builder extends StubSettings.Builder<AssetServiceStubSetting
     private final OperationCallSettings.Builder<
             ExportAssetsRequest, ExportAssetsResponse, ExportAssetsRequest>
         exportAssetsOperationSettings;
+    private final PagedCallSettings.Builder<
+            ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+        listAssetsSettings;
     private final UnaryCallSettings.Builder<
             BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
         batchGetAssetsHistorySettings;
@@ -486,9 +562,7 @@ public static class Builder extends StubSettings.Builder<AssetServiceStubSetting
                   StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
       definitions.put(
           "retry_policy_2_codes",
-          ImmutableSet.copyOf(
-              Lists.<StatusCode.Code>newArrayList(
-                  StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
+          ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList(StatusCode.Code.UNAVAILABLE)));
       definitions.put(
           "retry_policy_3_codes",
           ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList(StatusCode.Code.UNAVAILABLE)));
@@ -524,10 +598,10 @@ public static class Builder extends StubSettings.Builder<AssetServiceStubSetting
               .setInitialRetryDelay(Duration.ofMillis(100L))
               .setRetryDelayMultiplier(1.3)
               .setMaxRetryDelay(Duration.ofMillis(60000L))
-              .setInitialRpcTimeout(Duration.ofMillis(15000L))
+              .setInitialRpcTimeout(Duration.ofMillis(30000L))
               .setRpcTimeoutMultiplier(1.0)
-              .setMaxRpcTimeout(Duration.ofMillis(15000L))
-              .setTotalTimeout(Duration.ofMillis(15000L))
+              .setMaxRpcTimeout(Duration.ofMillis(30000L))
+              .setTotalTimeout(Duration.ofMillis(30000L))
               .build();
       definitions.put("retry_policy_2_params", settings);
       settings =
@@ -553,6 +627,7 @@ protected Builder(ClientContext clientContext) {
 
       exportAssetsSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
       exportAssetsOperationSettings = OperationCallSettings.newBuilder();
+      listAssetsSettings = PagedCallSettings.newBuilder(LIST_ASSETS_PAGE_STR_FACT);
       batchGetAssetsHistorySettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
       createFeedSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
       getFeedSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
@@ -569,6 +644,7 @@ protected Builder(ClientContext clientContext) {
       unaryMethodSettingsBuilders =
           ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
               exportAssetsSettings,
+              listAssetsSettings,
               batchGetAssetsHistorySettings,
               createFeedSettings,
               getFeedSettings,
@@ -587,6 +663,7 @@ protected Builder(AssetServiceStubSettings settings) {
 
       exportAssetsSettings = settings.exportAssetsSettings.toBuilder();
       exportAssetsOperationSettings = settings.exportAssetsOperationSettings.toBuilder();
+      listAssetsSettings = settings.listAssetsSettings.toBuilder();
       batchGetAssetsHistorySettings = settings.batchGetAssetsHistorySettings.toBuilder();
       createFeedSettings = settings.createFeedSettings.toBuilder();
       getFeedSettings = settings.getFeedSettings.toBuilder();
@@ -604,6 +681,7 @@ protected Builder(AssetServiceStubSettings settings) {
       unaryMethodSettingsBuilders =
           ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
               exportAssetsSettings,
+              listAssetsSettings,
               batchGetAssetsHistorySettings,
               createFeedSettings,
               getFeedSettings,
@@ -623,6 +701,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -633,6 +713,11 @@ private static Builder initDefaults(Builder builder) {
           .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_0_codes"))
           .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_0_params"));
 
+      builder
+          .listAssetsSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_1_params"));
+
       builder
           .batchGetAssetsHistorySettings()
           .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_1_codes"))
@@ -737,14 +822,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
@@ -767,6 +851,12 @@ public UnaryCallSettings.Builder<ExportAssetsRequest, Operation> exportAssetsSet
       return exportAssetsOperationSettings;
     }
 
+    /** Returns the builder for the settings used for calls to listAssets. */
+    public PagedCallSettings.Builder<ListAssetsRequest, ListAssetsResponse, ListAssetsPagedResponse>
+        listAssetsSettings() {
+      return listAssetsSettings;
+    }
+
     /** Returns the builder for the settings used for calls to batchGetAssetsHistory. */
     public UnaryCallSettings.Builder<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
         batchGetAssetsHistorySettings() {
diff --git a/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/GrpcAssetServiceStub.java b/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/GrpcAssetServiceStub.java
index 7fb9b4ba50..d884f02bf9 100644
--- a/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/GrpcAssetServiceStub.java
+++ b/test/integration/goldens/asset/com/google/cloud/asset/v1/stub/GrpcAssetServiceStub.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.asset.v1.stub;
 
+import static com.google.cloud.asset.v1.AssetServiceClient.ListAssetsPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllIamPoliciesPagedResponse;
 import static com.google.cloud.asset.v1.AssetServiceClient.SearchAllResourcesPagedResponse;
 
@@ -25,7 +26,6 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.cloud.asset.v1.AnalyzeIamPolicyLongrunningRequest;
 import com.google.cloud.asset.v1.AnalyzeIamPolicyLongrunningResponse;
@@ -39,6 +39,8 @@
 import com.google.cloud.asset.v1.ExportAssetsResponse;
 import com.google.cloud.asset.v1.Feed;
 import com.google.cloud.asset.v1.GetFeedRequest;
+import com.google.cloud.asset.v1.ListAssetsRequest;
+import com.google.cloud.asset.v1.ListAssetsResponse;
 import com.google.cloud.asset.v1.ListFeedsRequest;
 import com.google.cloud.asset.v1.ListFeedsResponse;
 import com.google.cloud.asset.v1.SearchAllIamPoliciesRequest;
@@ -74,6 +76,15 @@ public class GrpcAssetServiceStub extends AssetServiceStub {
               .setResponseMarshaller(ProtoUtils.marshaller(Operation.getDefaultInstance()))
               .build();
 
+  private static final MethodDescriptor<ListAssetsRequest, ListAssetsResponse>
+      listAssetsMethodDescriptor =
+          MethodDescriptor.<ListAssetsRequest, ListAssetsResponse>newBuilder()
+              .setType(MethodDescriptor.MethodType.UNARY)
+              .setFullMethodName("google.cloud.asset.v1.AssetService/ListAssets")
+              .setRequestMarshaller(ProtoUtils.marshaller(ListAssetsRequest.getDefaultInstance()))
+              .setResponseMarshaller(ProtoUtils.marshaller(ListAssetsResponse.getDefaultInstance()))
+              .build();
+
   private static final MethodDescriptor<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistoryMethodDescriptor =
           MethodDescriptor.<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>newBuilder()
@@ -172,6 +183,8 @@ public class GrpcAssetServiceStub extends AssetServiceStub {
   private final UnaryCallable<ExportAssetsRequest, Operation> exportAssetsCallable;
   private final OperationCallable<ExportAssetsRequest, ExportAssetsResponse, ExportAssetsRequest>
       exportAssetsOperationCallable;
+  private final UnaryCallable<ListAssetsRequest, ListAssetsResponse> listAssetsCallable;
+  private final UnaryCallable<ListAssetsRequest, ListAssetsPagedResponse> listAssetsPagedCallable;
   private final UnaryCallable<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistoryCallable;
   private final UnaryCallable<CreateFeedRequest, Feed> createFeedCallable;
@@ -243,13 +256,20 @@ protected GrpcAssetServiceStub(
         GrpcCallSettings.<ExportAssetsRequest, Operation>newBuilder()
             .setMethodDescriptor(exportAssetsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ExportAssetsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ExportAssetsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
+                })
+            .build();
+    GrpcCallSettings<ListAssetsRequest, ListAssetsResponse> listAssetsTransportSettings =
+        GrpcCallSettings.<ListAssetsRequest, ListAssetsResponse>newBuilder()
+            .setMethodDescriptor(listAssetsMethodDescriptor)
+            .setParamsExtractor(
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
@@ -258,78 +278,60 @@ public Map<String, String> extract(ExportAssetsRequest request) {
                 .<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>newBuilder()
                 .setMethodDescriptor(batchGetAssetsHistoryMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<BatchGetAssetsHistoryRequest>() {
-                      @Override
-                      public Map<String, String> extract(BatchGetAssetsHistoryRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<CreateFeedRequest, Feed> createFeedTransportSettings =
         GrpcCallSettings.<CreateFeedRequest, Feed>newBuilder()
             .setMethodDescriptor(createFeedMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateFeedRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateFeedRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetFeedRequest, Feed> getFeedTransportSettings =
         GrpcCallSettings.<GetFeedRequest, Feed>newBuilder()
             .setMethodDescriptor(getFeedMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetFeedRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetFeedRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListFeedsRequest, ListFeedsResponse> listFeedsTransportSettings =
         GrpcCallSettings.<ListFeedsRequest, ListFeedsResponse>newBuilder()
             .setMethodDescriptor(listFeedsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListFeedsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListFeedsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateFeedRequest, Feed> updateFeedTransportSettings =
         GrpcCallSettings.<UpdateFeedRequest, Feed>newBuilder()
             .setMethodDescriptor(updateFeedMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateFeedRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateFeedRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("feed.name", String.valueOf(request.getFeed().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("feed.name", String.valueOf(request.getFeed().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteFeedRequest, Empty> deleteFeedTransportSettings =
         GrpcCallSettings.<DeleteFeedRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteFeedMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteFeedRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteFeedRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<SearchAllResourcesRequest, SearchAllResourcesResponse>
@@ -337,13 +339,10 @@ public Map<String, String> extract(DeleteFeedRequest request) {
             GrpcCallSettings.<SearchAllResourcesRequest, SearchAllResourcesResponse>newBuilder()
                 .setMethodDescriptor(searchAllResourcesMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<SearchAllResourcesRequest>() {
-                      @Override
-                      public Map<String, String> extract(SearchAllResourcesRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("scope", String.valueOf(request.getScope()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("scope", String.valueOf(request.getScope()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<SearchAllIamPoliciesRequest, SearchAllIamPoliciesResponse>
@@ -351,13 +350,10 @@ public Map<String, String> extract(SearchAllResourcesRequest request) {
             GrpcCallSettings.<SearchAllIamPoliciesRequest, SearchAllIamPoliciesResponse>newBuilder()
                 .setMethodDescriptor(searchAllIamPoliciesMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<SearchAllIamPoliciesRequest>() {
-                      @Override
-                      public Map<String, String> extract(SearchAllIamPoliciesRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("scope", String.valueOf(request.getScope()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("scope", String.valueOf(request.getScope()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<AnalyzeIamPolicyRequest, AnalyzeIamPolicyResponse>
@@ -365,15 +361,12 @@ public Map<String, String> extract(SearchAllIamPoliciesRequest request) {
             GrpcCallSettings.<AnalyzeIamPolicyRequest, AnalyzeIamPolicyResponse>newBuilder()
                 .setMethodDescriptor(analyzeIamPolicyMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<AnalyzeIamPolicyRequest>() {
-                      @Override
-                      public Map<String, String> extract(AnalyzeIamPolicyRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put(
-                            "analysis_query.scope",
-                            String.valueOf(request.getAnalysisQuery().getScope()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put(
+                          "analysis_query.scope",
+                          String.valueOf(request.getAnalysisQuery().getScope()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<AnalyzeIamPolicyLongrunningRequest, Operation>
@@ -381,16 +374,12 @@ public Map<String, String> extract(AnalyzeIamPolicyRequest request) {
             GrpcCallSettings.<AnalyzeIamPolicyLongrunningRequest, Operation>newBuilder()
                 .setMethodDescriptor(analyzeIamPolicyLongrunningMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<AnalyzeIamPolicyLongrunningRequest>() {
-                      @Override
-                      public Map<String, String> extract(
-                          AnalyzeIamPolicyLongrunningRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put(
-                            "analysis_query.scope",
-                            String.valueOf(request.getAnalysisQuery().getScope()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put(
+                          "analysis_query.scope",
+                          String.valueOf(request.getAnalysisQuery().getScope()));
+                      return params.build();
                     })
                 .build();
 
@@ -403,6 +392,12 @@ public Map<String, String> extract(
             settings.exportAssetsOperationSettings(),
             clientContext,
             operationsStub);
+    this.listAssetsCallable =
+        callableFactory.createUnaryCallable(
+            listAssetsTransportSettings, settings.listAssetsSettings(), clientContext);
+    this.listAssetsPagedCallable =
+        callableFactory.createPagedCallable(
+            listAssetsTransportSettings, settings.listAssetsSettings(), clientContext);
     this.batchGetAssetsHistoryCallable =
         callableFactory.createUnaryCallable(
             batchGetAssetsHistoryTransportSettings,
@@ -477,6 +472,16 @@ public UnaryCallable<ExportAssetsRequest, Operation> exportAssetsCallable() {
     return exportAssetsOperationCallable;
   }
 
+  @Override
+  public UnaryCallable<ListAssetsRequest, ListAssetsResponse> listAssetsCallable() {
+    return listAssetsCallable;
+  }
+
+  @Override
+  public UnaryCallable<ListAssetsRequest, ListAssetsPagedResponse> listAssetsPagedCallable() {
+    return listAssetsPagedCallable;
+  }
+
   @Override
   public UnaryCallable<BatchGetAssetsHistoryRequest, BatchGetAssetsHistoryResponse>
       batchGetAssetsHistoryCallable() {
@@ -555,7 +560,13 @@ public UnaryCallable<DeleteFeedRequest, Empty> deleteFeedCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/compute/BUILD.bazel b/test/integration/goldens/compute/BUILD.bazel
new file mode 100644
index 0000000000..2822013159
--- /dev/null
+++ b/test/integration/goldens/compute/BUILD.bazel
@@ -0,0 +1,12 @@
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "goldens_files",
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
+)
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesClient.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesClient.java
new file mode 100644
index 0000000000..eb9db7ce24
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesClient.java
@@ -0,0 +1,757 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1;
+
+import com.google.api.core.ApiFuture;
+import com.google.api.core.ApiFutures;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.paging.AbstractFixedSizeCollection;
+import com.google.api.gax.paging.AbstractPage;
+import com.google.api.gax.paging.AbstractPagedListResponse;
+import com.google.api.gax.rpc.PageContext;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.stub.AddressesStub;
+import com.google.cloud.compute.v1.stub.AddressesStubSettings;
+import com.google.common.util.concurrent.MoreExecutors;
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Service Description: Services
+ *
+ * <p>The Addresses API.
+ *
+ * <p>This class provides the ability to make remote calls to the backing service through method
+ * calls that map to API methods. Sample code to get started:
+ *
+ * <pre>{@code
+ * try (AddressesClient addressesClient = AddressesClient.create()) {
+ *   String project = "project-309310695";
+ *   String region = "region-934795532";
+ *   String address = "address-1147692044";
+ *   Operation response = addressesClient.delete(project, region, address);
+ * }
+ * }</pre>
+ *
+ * <p>Note: close() needs to be called on the AddressesClient object to clean up resources such as
+ * threads. In the example above, try-with-resources is used, which automatically calls close().
+ *
+ * <p>The surface of this class includes several types of Java methods for each of the API's
+ * methods:
+ *
+ * <ol>
+ *   <li>A "flattened" method. With this type of method, the fields of the request type have been
+ *       converted into function parameters. It may be the case that not all fields are available as
+ *       parameters, and not every API method will have a flattened method entry point.
+ *   <li>A "request object" method. This type of method only takes one parameter, a request object,
+ *       which must be constructed before the call. Not every API method will have a request object
+ *       method.
+ *   <li>A "callable" method. This type of method takes no parameters and returns an immutable API
+ *       callable object, which can be used to initiate calls to the service.
+ * </ol>
+ *
+ * <p>See the individual methods for example code.
+ *
+ * <p>Many parameters require resource names to be formatted in a particular way. To assist with
+ * these names, this class includes a format method for each type of name, and additionally a parse
+ * method to extract the individual identifiers contained within names that are returned.
+ *
+ * <p>This class can be customized by passing in a custom instance of AddressesSettings to create().
+ * For example:
+ *
+ * <p>To customize credentials:
+ *
+ * <pre>{@code
+ * AddressesSettings addressesSettings =
+ *     AddressesSettings.newBuilder()
+ *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
+ *         .build();
+ * AddressesClient addressesClient = AddressesClient.create(addressesSettings);
+ * }</pre>
+ *
+ * <p>To customize the endpoint:
+ *
+ * <pre>{@code
+ * AddressesSettings addressesSettings =
+ *     AddressesSettings.newBuilder().setEndpoint(myEndpoint).build();
+ * AddressesClient addressesClient = AddressesClient.create(addressesSettings);
+ * }</pre>
+ *
+ * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
+ */
+@Generated("by gapic-generator-java")
+public class AddressesClient implements BackgroundResource {
+  private final AddressesSettings settings;
+  private final AddressesStub stub;
+
+  /** Constructs an instance of AddressesClient with default settings. */
+  public static final AddressesClient create() throws IOException {
+    return create(AddressesSettings.newBuilder().build());
+  }
+
+  /**
+   * Constructs an instance of AddressesClient, using the given settings. The channels are created
+   * based on the settings passed in, or defaults for any settings that are not set.
+   */
+  public static final AddressesClient create(AddressesSettings settings) throws IOException {
+    return new AddressesClient(settings);
+  }
+
+  /**
+   * Constructs an instance of AddressesClient, using the given stub for making calls. This is for
+   * advanced usage - prefer using create(AddressesSettings).
+   */
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public static final AddressesClient create(AddressesStub stub) {
+    return new AddressesClient(stub);
+  }
+
+  /**
+   * Constructs an instance of AddressesClient, using the given settings. This is protected so that
+   * it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
+   */
+  protected AddressesClient(AddressesSettings settings) throws IOException {
+    this.settings = settings;
+    this.stub = ((AddressesStubSettings) settings.getStubSettings()).createStub();
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  protected AddressesClient(AddressesStub stub) {
+    this.settings = null;
+    this.stub = stub;
+  }
+
+  public final AddressesSettings getSettings() {
+    return settings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public AddressesStub getStub() {
+    return stub;
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves an aggregated list of addresses.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   String project = "project-309310695";
+   *   for (Map.Entry<String, AddressesScopedList> element :
+   *       addressesClient.aggregatedList(project).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param project Project ID for this request.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final AggregatedListPagedResponse aggregatedList(String project) {
+    AggregatedListAddressesRequest request =
+        AggregatedListAddressesRequest.newBuilder().setProject(project).build();
+    return aggregatedList(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves an aggregated list of addresses.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   AggregatedListAddressesRequest request =
+   *       AggregatedListAddressesRequest.newBuilder()
+   *           .setFilter("filter-1274492040")
+   *           .setIncludeAllScopes(true)
+   *           .setMaxResults(1128457243)
+   *           .setOrderBy("orderBy-1207110587")
+   *           .setPageToken("pageToken873572522")
+   *           .setProject("project-309310695")
+   *           .build();
+   *   for (Map.Entry<String, AddressesScopedList> element :
+   *       addressesClient.aggregatedList(request).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final AggregatedListPagedResponse aggregatedList(AggregatedListAddressesRequest request) {
+    return aggregatedListPagedCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves an aggregated list of addresses.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   AggregatedListAddressesRequest request =
+   *       AggregatedListAddressesRequest.newBuilder()
+   *           .setFilter("filter-1274492040")
+   *           .setIncludeAllScopes(true)
+   *           .setMaxResults(1128457243)
+   *           .setOrderBy("orderBy-1207110587")
+   *           .setPageToken("pageToken873572522")
+   *           .setProject("project-309310695")
+   *           .build();
+   *   ApiFuture<Map.Entry<String, AddressesScopedList>> future =
+   *       addressesClient.aggregatedListPagedCallable().futureCall(request);
+   *   // Do something.
+   *   for (Map.Entry<String, AddressesScopedList> element : future.get().iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<AggregatedListAddressesRequest, AggregatedListPagedResponse>
+      aggregatedListPagedCallable() {
+    return stub.aggregatedListPagedCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves an aggregated list of addresses.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   AggregatedListAddressesRequest request =
+   *       AggregatedListAddressesRequest.newBuilder()
+   *           .setFilter("filter-1274492040")
+   *           .setIncludeAllScopes(true)
+   *           .setMaxResults(1128457243)
+   *           .setOrderBy("orderBy-1207110587")
+   *           .setPageToken("pageToken873572522")
+   *           .setProject("project-309310695")
+   *           .build();
+   *   while (true) {
+   *     AddressAggregatedList response = addressesClient.aggregatedListCallable().call(request);
+   *     for (Map.Entry<String, AddressesScopedList> element : response.getResponsesList()) {
+   *       // doThingsWith(element);
+   *     }
+   *     String nextPageToken = response.getNextPageToken();
+   *     if (!Strings.isNullOrEmpty(nextPageToken)) {
+   *       request = request.toBuilder().setPageToken(nextPageToken).build();
+   *     } else {
+   *       break;
+   *     }
+   *   }
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<AggregatedListAddressesRequest, AddressAggregatedList>
+      aggregatedListCallable() {
+    return stub.aggregatedListCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Deletes the specified address resource.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   String project = "project-309310695";
+   *   String region = "region-934795532";
+   *   String address = "address-1147692044";
+   *   Operation response = addressesClient.delete(project, region, address);
+   * }
+   * }</pre>
+   *
+   * @param project Project ID for this request.
+   * @param region Name of the region for this request.
+   * @param address Name of the address resource to delete.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Operation delete(String project, String region, String address) {
+    DeleteAddressRequest request =
+        DeleteAddressRequest.newBuilder()
+            .setProject(project)
+            .setRegion(region)
+            .setAddress(address)
+            .build();
+    return delete(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Deletes the specified address resource.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   DeleteAddressRequest request =
+   *       DeleteAddressRequest.newBuilder()
+   *           .setAddress("address-1147692044")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .setRequestId("requestId693933066")
+   *           .build();
+   *   Operation response = addressesClient.delete(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Operation delete(DeleteAddressRequest request) {
+    return deleteCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Deletes the specified address resource.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   DeleteAddressRequest request =
+   *       DeleteAddressRequest.newBuilder()
+   *           .setAddress("address-1147692044")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .setRequestId("requestId693933066")
+   *           .build();
+   *   ApiFuture<Operation> future = addressesClient.deleteCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<DeleteAddressRequest, Operation> deleteCallable() {
+    return stub.deleteCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Creates an address resource in the specified project by using the data included in the request.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   String project = "project-309310695";
+   *   String region = "region-934795532";
+   *   Address addressResource = Address.newBuilder().build();
+   *   Operation response = addressesClient.insert(project, region, addressResource);
+   * }
+   * }</pre>
+   *
+   * @param project Project ID for this request.
+   * @param region Name of the region for this request.
+   * @param addressResource The body resource for this request
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Operation insert(String project, String region, Address addressResource) {
+    InsertAddressRequest request =
+        InsertAddressRequest.newBuilder()
+            .setProject(project)
+            .setRegion(region)
+            .setAddressResource(addressResource)
+            .build();
+    return insert(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Creates an address resource in the specified project by using the data included in the request.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   InsertAddressRequest request =
+   *       InsertAddressRequest.newBuilder()
+   *           .setAddressResource(Address.newBuilder().build())
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .setRequestId("requestId693933066")
+   *           .build();
+   *   Operation response = addressesClient.insert(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Operation insert(InsertAddressRequest request) {
+    return insertCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Creates an address resource in the specified project by using the data included in the request.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   InsertAddressRequest request =
+   *       InsertAddressRequest.newBuilder()
+   *           .setAddressResource(Address.newBuilder().build())
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .setRequestId("requestId693933066")
+   *           .build();
+   *   ApiFuture<Operation> future = addressesClient.insertCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<InsertAddressRequest, Operation> insertCallable() {
+    return stub.insertCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves a list of addresses contained within the specified region.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   String project = "project-309310695";
+   *   String region = "region-934795532";
+   *   String orderBy = "orderBy-1207110587";
+   *   for (Address element : addressesClient.list(project, region, orderBy).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param project Project ID for this request.
+   * @param region Name of the region for this request.
+   * @param orderBy Sorts list results by a certain order. By default, results are returned in
+   *     alphanumerical order based on the resource name.
+   *     <p>You can also sort results in descending order based on the creation timestamp using
+   *     orderBy="creationTimestamp desc". This sorts results based on the creationTimestamp field
+   *     in reverse chronological order (newest result first). Use this to sort resources like
+   *     operations so that the newest operation is returned first.
+   *     <p>Currently, only sorting by name or creationTimestamp desc is supported.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final ListPagedResponse list(String project, String region, String orderBy) {
+    ListAddressesRequest request =
+        ListAddressesRequest.newBuilder()
+            .setProject(project)
+            .setRegion(region)
+            .setOrderBy(orderBy)
+            .build();
+    return list(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves a list of addresses contained within the specified region.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   ListAddressesRequest request =
+   *       ListAddressesRequest.newBuilder()
+   *           .setFilter("filter-1274492040")
+   *           .setMaxResults(1128457243)
+   *           .setOrderBy("orderBy-1207110587")
+   *           .setPageToken("pageToken873572522")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .build();
+   *   for (Address element : addressesClient.list(request).iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final ListPagedResponse list(ListAddressesRequest request) {
+    return listPagedCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves a list of addresses contained within the specified region.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   ListAddressesRequest request =
+   *       ListAddressesRequest.newBuilder()
+   *           .setFilter("filter-1274492040")
+   *           .setMaxResults(1128457243)
+   *           .setOrderBy("orderBy-1207110587")
+   *           .setPageToken("pageToken873572522")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .build();
+   *   ApiFuture<Address> future = addressesClient.listPagedCallable().futureCall(request);
+   *   // Do something.
+   *   for (Address element : future.get().iterateAll()) {
+   *     // doThingsWith(element);
+   *   }
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<ListAddressesRequest, ListPagedResponse> listPagedCallable() {
+    return stub.listPagedCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves a list of addresses contained within the specified region.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (AddressesClient addressesClient = AddressesClient.create()) {
+   *   ListAddressesRequest request =
+   *       ListAddressesRequest.newBuilder()
+   *           .setFilter("filter-1274492040")
+   *           .setMaxResults(1128457243)
+   *           .setOrderBy("orderBy-1207110587")
+   *           .setPageToken("pageToken873572522")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .build();
+   *   while (true) {
+   *     AddressList response = addressesClient.listCallable().call(request);
+   *     for (Address element : response.getResponsesList()) {
+   *       // doThingsWith(element);
+   *     }
+   *     String nextPageToken = response.getNextPageToken();
+   *     if (!Strings.isNullOrEmpty(nextPageToken)) {
+   *       request = request.toBuilder().setPageToken(nextPageToken).build();
+   *     } else {
+   *       break;
+   *     }
+   *   }
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<ListAddressesRequest, AddressList> listCallable() {
+    return stub.listCallable();
+  }
+
+  @Override
+  public final void close() {
+    stub.close();
+  }
+
+  @Override
+  public void shutdown() {
+    stub.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return stub.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return stub.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    stub.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return stub.awaitTermination(duration, unit);
+  }
+
+  public static class AggregatedListPagedResponse
+      extends AbstractPagedListResponse<
+          AggregatedListAddressesRequest,
+          AddressAggregatedList,
+          Map.Entry<String, AddressesScopedList>,
+          AggregatedListPage,
+          AggregatedListFixedSizeCollection> {
+
+    public static ApiFuture<AggregatedListPagedResponse> createAsync(
+        PageContext<
+                AggregatedListAddressesRequest,
+                AddressAggregatedList,
+                Map.Entry<String, AddressesScopedList>>
+            context,
+        ApiFuture<AddressAggregatedList> futureResponse) {
+      ApiFuture<AggregatedListPage> futurePage =
+          AggregatedListPage.createEmptyPage().createPageAsync(context, futureResponse);
+      return ApiFutures.transform(
+          futurePage,
+          input -> new AggregatedListPagedResponse(input),
+          MoreExecutors.directExecutor());
+    }
+
+    private AggregatedListPagedResponse(AggregatedListPage page) {
+      super(page, AggregatedListFixedSizeCollection.createEmptyCollection());
+    }
+  }
+
+  public static class AggregatedListPage
+      extends AbstractPage<
+          AggregatedListAddressesRequest,
+          AddressAggregatedList,
+          Map.Entry<String, AddressesScopedList>,
+          AggregatedListPage> {
+
+    private AggregatedListPage(
+        PageContext<
+                AggregatedListAddressesRequest,
+                AddressAggregatedList,
+                Map.Entry<String, AddressesScopedList>>
+            context,
+        AddressAggregatedList response) {
+      super(context, response);
+    }
+
+    private static AggregatedListPage createEmptyPage() {
+      return new AggregatedListPage(null, null);
+    }
+
+    @Override
+    protected AggregatedListPage createPage(
+        PageContext<
+                AggregatedListAddressesRequest,
+                AddressAggregatedList,
+                Map.Entry<String, AddressesScopedList>>
+            context,
+        AddressAggregatedList response) {
+      return new AggregatedListPage(context, response);
+    }
+
+    @Override
+    public ApiFuture<AggregatedListPage> createPageAsync(
+        PageContext<
+                AggregatedListAddressesRequest,
+                AddressAggregatedList,
+                Map.Entry<String, AddressesScopedList>>
+            context,
+        ApiFuture<AddressAggregatedList> futureResponse) {
+      return super.createPageAsync(context, futureResponse);
+    }
+  }
+
+  public static class AggregatedListFixedSizeCollection
+      extends AbstractFixedSizeCollection<
+          AggregatedListAddressesRequest,
+          AddressAggregatedList,
+          Map.Entry<String, AddressesScopedList>,
+          AggregatedListPage,
+          AggregatedListFixedSizeCollection> {
+
+    private AggregatedListFixedSizeCollection(List<AggregatedListPage> pages, int collectionSize) {
+      super(pages, collectionSize);
+    }
+
+    private static AggregatedListFixedSizeCollection createEmptyCollection() {
+      return new AggregatedListFixedSizeCollection(null, 0);
+    }
+
+    @Override
+    protected AggregatedListFixedSizeCollection createCollection(
+        List<AggregatedListPage> pages, int collectionSize) {
+      return new AggregatedListFixedSizeCollection(pages, collectionSize);
+    }
+  }
+
+  public static class ListPagedResponse
+      extends AbstractPagedListResponse<
+          ListAddressesRequest, AddressList, Address, ListPage, ListFixedSizeCollection> {
+
+    public static ApiFuture<ListPagedResponse> createAsync(
+        PageContext<ListAddressesRequest, AddressList, Address> context,
+        ApiFuture<AddressList> futureResponse) {
+      ApiFuture<ListPage> futurePage =
+          ListPage.createEmptyPage().createPageAsync(context, futureResponse);
+      return ApiFutures.transform(
+          futurePage, input -> new ListPagedResponse(input), MoreExecutors.directExecutor());
+    }
+
+    private ListPagedResponse(ListPage page) {
+      super(page, ListFixedSizeCollection.createEmptyCollection());
+    }
+  }
+
+  public static class ListPage
+      extends AbstractPage<ListAddressesRequest, AddressList, Address, ListPage> {
+
+    private ListPage(
+        PageContext<ListAddressesRequest, AddressList, Address> context, AddressList response) {
+      super(context, response);
+    }
+
+    private static ListPage createEmptyPage() {
+      return new ListPage(null, null);
+    }
+
+    @Override
+    protected ListPage createPage(
+        PageContext<ListAddressesRequest, AddressList, Address> context, AddressList response) {
+      return new ListPage(context, response);
+    }
+
+    @Override
+    public ApiFuture<ListPage> createPageAsync(
+        PageContext<ListAddressesRequest, AddressList, Address> context,
+        ApiFuture<AddressList> futureResponse) {
+      return super.createPageAsync(context, futureResponse);
+    }
+  }
+
+  public static class ListFixedSizeCollection
+      extends AbstractFixedSizeCollection<
+          ListAddressesRequest, AddressList, Address, ListPage, ListFixedSizeCollection> {
+
+    private ListFixedSizeCollection(List<ListPage> pages, int collectionSize) {
+      super(pages, collectionSize);
+    }
+
+    private static ListFixedSizeCollection createEmptyCollection() {
+      return new ListFixedSizeCollection(null, 0);
+    }
+
+    @Override
+    protected ListFixedSizeCollection createCollection(List<ListPage> pages, int collectionSize) {
+      return new ListFixedSizeCollection(pages, collectionSize);
+    }
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesClientTest.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesClientTest.java
new file mode 100644
index 0000000000..bc7d9c2a16
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesClientTest.java
@@ -0,0 +1,324 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1;
+
+import static com.google.cloud.compute.v1.AddressesClient.AggregatedListPagedResponse;
+import static com.google.cloud.compute.v1.AddressesClient.ListPagedResponse;
+
+import com.google.api.gax.core.NoCredentialsProvider;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.testing.MockHttpService;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ApiException;
+import com.google.api.gax.rpc.ApiExceptionFactory;
+import com.google.api.gax.rpc.InvalidArgumentException;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.testing.FakeStatusCode;
+import com.google.cloud.compute.v1.stub.HttpJsonAddressesStub;
+import com.google.common.collect.Lists;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import javax.annotation.Generated;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+@Generated("by gapic-generator-java")
+public class AddressesClientTest {
+  private static MockHttpService mockService;
+  private static AddressesClient client;
+
+  @BeforeClass
+  public static void startStaticServer() throws IOException {
+    mockService =
+        new MockHttpService(
+            HttpJsonAddressesStub.getMethodDescriptors(), AddressesSettings.getDefaultEndpoint());
+    AddressesSettings settings =
+        AddressesSettings.newBuilder()
+            .setTransportChannelProvider(
+                AddressesSettings.defaultHttpJsonTransportProviderBuilder()
+                    .setHttpTransport(mockService)
+                    .build())
+            .setCredentialsProvider(NoCredentialsProvider.create())
+            .build();
+    client = AddressesClient.create(settings);
+  }
+
+  @AfterClass
+  public static void stopServer() {
+    client.close();
+  }
+
+  @Before
+  public void setUp() {}
+
+  @After
+  public void tearDown() throws Exception {
+    mockService.reset();
+  }
+
+  @Test
+  public void aggregatedListTest() throws Exception {
+    AddressesScopedList responsesElement = AddressesScopedList.newBuilder().build();
+    AddressAggregatedList expectedResponse =
+        AddressAggregatedList.newBuilder()
+            .setNextPageToken("")
+            .putAllItems(Collections.singletonMap("items", responsesElement))
+            .build();
+    mockService.addResponse(expectedResponse);
+
+    String project = "project-309310695";
+
+    AggregatedListPagedResponse pagedListResponse = client.aggregatedList(project);
+
+    List<Map.Entry<String, AddressesScopedList>> resources =
+        Lists.newArrayList(pagedListResponse.iterateAll());
+
+    Assert.assertEquals(1, resources.size());
+    Assert.assertEquals(
+        expectedResponse.getItemsMap().entrySet().iterator().next(), resources.get(0));
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void aggregatedListExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      String project = "project-309310695";
+      client.aggregatedList(project);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void deleteTest() throws Exception {
+    Operation expectedResponse =
+        Operation.newBuilder()
+            .setClientOperationId("clientOperationId-1230366697")
+            .setCreationTimestamp("creationTimestamp-370203401")
+            .setDescription("description-1724546052")
+            .setEndTime("endTime-1607243192")
+            .setError(Error.newBuilder().build())
+            .setHttpErrorMessage("httpErrorMessage1577303431")
+            .setHttpErrorStatusCode(1386087020)
+            .setId("id3355")
+            .setInsertTime("insertTime966165798")
+            .setKind("kind3292052")
+            .setName("name3373707")
+            .setOperationType("operationType91999553")
+            .setProgress(-1001078227)
+            .setRegion("region-934795532")
+            .setSelfLink("selfLink1191800166")
+            .setStartTime("startTime-2129294769")
+            .setStatusMessage("statusMessage-958704715")
+            .setTargetId("targetId-441951604")
+            .setTargetLink("targetLink486368555")
+            .setUser("user3599307")
+            .addAllWarnings(new ArrayList<Warnings>())
+            .setZone("zone3744684")
+            .build();
+    mockService.addResponse(expectedResponse);
+
+    String project = "project-309310695";
+    String region = "region-934795532";
+    String address = "address-1147692044";
+
+    Operation actualResponse = client.delete(project, region, address);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void deleteExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      String project = "project-309310695";
+      String region = "region-934795532";
+      String address = "address-1147692044";
+      client.delete(project, region, address);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void insertTest() throws Exception {
+    Operation expectedResponse =
+        Operation.newBuilder()
+            .setClientOperationId("clientOperationId-1230366697")
+            .setCreationTimestamp("creationTimestamp-370203401")
+            .setDescription("description-1724546052")
+            .setEndTime("endTime-1607243192")
+            .setError(Error.newBuilder().build())
+            .setHttpErrorMessage("httpErrorMessage1577303431")
+            .setHttpErrorStatusCode(1386087020)
+            .setId("id3355")
+            .setInsertTime("insertTime966165798")
+            .setKind("kind3292052")
+            .setName("name3373707")
+            .setOperationType("operationType91999553")
+            .setProgress(-1001078227)
+            .setRegion("region-934795532")
+            .setSelfLink("selfLink1191800166")
+            .setStartTime("startTime-2129294769")
+            .setStatusMessage("statusMessage-958704715")
+            .setTargetId("targetId-441951604")
+            .setTargetLink("targetLink486368555")
+            .setUser("user3599307")
+            .addAllWarnings(new ArrayList<Warnings>())
+            .setZone("zone3744684")
+            .build();
+    mockService.addResponse(expectedResponse);
+
+    String project = "project-309310695";
+    String region = "region-934795532";
+    Address addressResource = Address.newBuilder().build();
+
+    Operation actualResponse = client.insert(project, region, addressResource);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void insertExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      String project = "project-309310695";
+      String region = "region-934795532";
+      Address addressResource = Address.newBuilder().build();
+      client.insert(project, region, addressResource);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void listTest() throws Exception {
+    Address responsesElement = Address.newBuilder().build();
+    AddressList expectedResponse =
+        AddressList.newBuilder()
+            .setNextPageToken("")
+            .addAllItems(Arrays.asList(responsesElement))
+            .build();
+    mockService.addResponse(expectedResponse);
+
+    String project = "project-309310695";
+    String region = "region-934795532";
+    String orderBy = "orderBy-1207110587";
+
+    ListPagedResponse pagedListResponse = client.list(project, region, orderBy);
+
+    List<Address> resources = Lists.newArrayList(pagedListResponse.iterateAll());
+
+    Assert.assertEquals(1, resources.size());
+    Assert.assertEquals(expectedResponse.getItemsList().get(0), resources.get(0));
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void listExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      String project = "project-309310695";
+      String region = "region-934795532";
+      String orderBy = "orderBy-1207110587";
+      client.list(project, region, orderBy);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesSettings.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesSettings.java
new file mode 100644
index 0000000000..d2dc359f73
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/AddressesSettings.java
@@ -0,0 +1,220 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1;
+
+import static com.google.cloud.compute.v1.AddressesClient.AggregatedListPagedResponse;
+import static com.google.cloud.compute.v1.AddressesClient.ListPagedResponse;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientSettings;
+import com.google.api.gax.rpc.PagedCallSettings;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.cloud.compute.v1.stub.AddressesStubSettings;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link AddressesClient}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (compute.googleapis.com) and default port (443) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of delete to 30 seconds:
+ *
+ * <pre>{@code
+ * AddressesSettings.Builder addressesSettingsBuilder = AddressesSettings.newBuilder();
+ * addressesSettingsBuilder
+ *     .deleteSettings()
+ *     .setRetrySettings(
+ *         addressesSettingsBuilder
+ *             .deleteSettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * AddressesSettings addressesSettings = addressesSettingsBuilder.build();
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+public class AddressesSettings extends ClientSettings<AddressesSettings> {
+
+  /** Returns the object with the settings used for calls to aggregatedList. */
+  public PagedCallSettings<
+          AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+      aggregatedListSettings() {
+    return ((AddressesStubSettings) getStubSettings()).aggregatedListSettings();
+  }
+
+  /** Returns the object with the settings used for calls to delete. */
+  public UnaryCallSettings<DeleteAddressRequest, Operation> deleteSettings() {
+    return ((AddressesStubSettings) getStubSettings()).deleteSettings();
+  }
+
+  /** Returns the object with the settings used for calls to insert. */
+  public UnaryCallSettings<InsertAddressRequest, Operation> insertSettings() {
+    return ((AddressesStubSettings) getStubSettings()).insertSettings();
+  }
+
+  /** Returns the object with the settings used for calls to list. */
+  public PagedCallSettings<ListAddressesRequest, AddressList, ListPagedResponse> listSettings() {
+    return ((AddressesStubSettings) getStubSettings()).listSettings();
+  }
+
+  public static final AddressesSettings create(AddressesStubSettings stub) throws IOException {
+    return new AddressesSettings.Builder(stub.toBuilder()).build();
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return AddressesStubSettings.defaultExecutorProviderBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return AddressesStubSettings.getDefaultEndpoint();
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return AddressesStubSettings.getDefaultServiceScopes();
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return AddressesStubSettings.defaultCredentialsProviderBuilder();
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return AddressesStubSettings.defaultHttpJsonTransportProviderBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return AddressesStubSettings.defaultTransportChannelProvider();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return AddressesStubSettings.defaultApiClientHeaderProviderBuilder();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected AddressesSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+  }
+
+  /** Builder for AddressesSettings. */
+  public static class Builder extends ClientSettings.Builder<AddressesSettings, Builder> {
+
+    protected Builder() throws IOException {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(AddressesStubSettings.newBuilder(clientContext));
+    }
+
+    protected Builder(AddressesSettings settings) {
+      super(settings.getStubSettings().toBuilder());
+    }
+
+    protected Builder(AddressesStubSettings.Builder stubSettings) {
+      super(stubSettings);
+    }
+
+    private static Builder createDefault() {
+      return new Builder(AddressesStubSettings.newBuilder());
+    }
+
+    public AddressesStubSettings.Builder getStubSettingsBuilder() {
+      return ((AddressesStubSettings.Builder) getStubSettings());
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(
+          getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
+      return this;
+    }
+
+    /** Returns the builder for the settings used for calls to aggregatedList. */
+    public PagedCallSettings.Builder<
+            AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+        aggregatedListSettings() {
+      return getStubSettingsBuilder().aggregatedListSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to delete. */
+    public UnaryCallSettings.Builder<DeleteAddressRequest, Operation> deleteSettings() {
+      return getStubSettingsBuilder().deleteSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to insert. */
+    public UnaryCallSettings.Builder<InsertAddressRequest, Operation> insertSettings() {
+      return getStubSettingsBuilder().insertSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to list. */
+    public PagedCallSettings.Builder<ListAddressesRequest, AddressList, ListPagedResponse>
+        listSettings() {
+      return getStubSettingsBuilder().listSettings();
+    }
+
+    @Override
+    public AddressesSettings build() throws IOException {
+      return new AddressesSettings(this);
+    }
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsClient.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsClient.java
new file mode 100644
index 0000000000..fb6a5e296d
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsClient.java
@@ -0,0 +1,254 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.stub.RegionOperationsStub;
+import com.google.cloud.compute.v1.stub.RegionOperationsStubSettings;
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Service Description: The RegionOperations API.
+ *
+ * <p>This class provides the ability to make remote calls to the backing service through method
+ * calls that map to API methods. Sample code to get started:
+ *
+ * <pre>{@code
+ * try (RegionOperationsClient regionOperationsClient = RegionOperationsClient.create()) {
+ *   String project = "project-309310695";
+ *   String region = "region-934795532";
+ *   String operation = "operation1662702951";
+ *   Operation response = regionOperationsClient.get(project, region, operation);
+ * }
+ * }</pre>
+ *
+ * <p>Note: close() needs to be called on the RegionOperationsClient object to clean up resources
+ * such as threads. In the example above, try-with-resources is used, which automatically calls
+ * close().
+ *
+ * <p>The surface of this class includes several types of Java methods for each of the API's
+ * methods:
+ *
+ * <ol>
+ *   <li>A "flattened" method. With this type of method, the fields of the request type have been
+ *       converted into function parameters. It may be the case that not all fields are available as
+ *       parameters, and not every API method will have a flattened method entry point.
+ *   <li>A "request object" method. This type of method only takes one parameter, a request object,
+ *       which must be constructed before the call. Not every API method will have a request object
+ *       method.
+ *   <li>A "callable" method. This type of method takes no parameters and returns an immutable API
+ *       callable object, which can be used to initiate calls to the service.
+ * </ol>
+ *
+ * <p>See the individual methods for example code.
+ *
+ * <p>Many parameters require resource names to be formatted in a particular way. To assist with
+ * these names, this class includes a format method for each type of name, and additionally a parse
+ * method to extract the individual identifiers contained within names that are returned.
+ *
+ * <p>This class can be customized by passing in a custom instance of RegionOperationsSettings to
+ * create(). For example:
+ *
+ * <p>To customize credentials:
+ *
+ * <pre>{@code
+ * RegionOperationsSettings regionOperationsSettings =
+ *     RegionOperationsSettings.newBuilder()
+ *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
+ *         .build();
+ * RegionOperationsClient regionOperationsClient =
+ *     RegionOperationsClient.create(regionOperationsSettings);
+ * }</pre>
+ *
+ * <p>To customize the endpoint:
+ *
+ * <pre>{@code
+ * RegionOperationsSettings regionOperationsSettings =
+ *     RegionOperationsSettings.newBuilder().setEndpoint(myEndpoint).build();
+ * RegionOperationsClient regionOperationsClient =
+ *     RegionOperationsClient.create(regionOperationsSettings);
+ * }</pre>
+ *
+ * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
+ */
+@Generated("by gapic-generator-java")
+public class RegionOperationsClient implements BackgroundResource {
+  private final RegionOperationsSettings settings;
+  private final RegionOperationsStub stub;
+
+  /** Constructs an instance of RegionOperationsClient with default settings. */
+  public static final RegionOperationsClient create() throws IOException {
+    return create(RegionOperationsSettings.newBuilder().build());
+  }
+
+  /**
+   * Constructs an instance of RegionOperationsClient, using the given settings. The channels are
+   * created based on the settings passed in, or defaults for any settings that are not set.
+   */
+  public static final RegionOperationsClient create(RegionOperationsSettings settings)
+      throws IOException {
+    return new RegionOperationsClient(settings);
+  }
+
+  /**
+   * Constructs an instance of RegionOperationsClient, using the given stub for making calls. This
+   * is for advanced usage - prefer using create(RegionOperationsSettings).
+   */
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public static final RegionOperationsClient create(RegionOperationsStub stub) {
+    return new RegionOperationsClient(stub);
+  }
+
+  /**
+   * Constructs an instance of RegionOperationsClient, using the given settings. This is protected
+   * so that it is easy to make a subclass, but otherwise, the static factory methods should be
+   * preferred.
+   */
+  protected RegionOperationsClient(RegionOperationsSettings settings) throws IOException {
+    this.settings = settings;
+    this.stub = ((RegionOperationsStubSettings) settings.getStubSettings()).createStub();
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  protected RegionOperationsClient(RegionOperationsStub stub) {
+    this.settings = null;
+    this.stub = stub;
+  }
+
+  public final RegionOperationsSettings getSettings() {
+    return settings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public RegionOperationsStub getStub() {
+    return stub;
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves the specified region-specific Operations resource.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (RegionOperationsClient regionOperationsClient = RegionOperationsClient.create()) {
+   *   String project = "project-309310695";
+   *   String region = "region-934795532";
+   *   String operation = "operation1662702951";
+   *   Operation response = regionOperationsClient.get(project, region, operation);
+   * }
+   * }</pre>
+   *
+   * @param project Project ID for this request.
+   * @param region Name of the region for this request.
+   * @param operation Name of the Operations resource to return.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Operation get(String project, String region, String operation) {
+    GetRegionOperationRequest request =
+        GetRegionOperationRequest.newBuilder()
+            .setProject(project)
+            .setRegion(region)
+            .setOperation(operation)
+            .build();
+    return get(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves the specified region-specific Operations resource.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (RegionOperationsClient regionOperationsClient = RegionOperationsClient.create()) {
+   *   GetRegionOperationRequest request =
+   *       GetRegionOperationRequest.newBuilder()
+   *           .setOperation("operation1662702951")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .build();
+   *   Operation response = regionOperationsClient.get(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final Operation get(GetRegionOperationRequest request) {
+    return getCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Retrieves the specified region-specific Operations resource.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (RegionOperationsClient regionOperationsClient = RegionOperationsClient.create()) {
+   *   GetRegionOperationRequest request =
+   *       GetRegionOperationRequest.newBuilder()
+   *           .setOperation("operation1662702951")
+   *           .setProject("project-309310695")
+   *           .setRegion("region-934795532")
+   *           .build();
+   *   ApiFuture<Operation> future = regionOperationsClient.getCallable().futureCall(request);
+   *   // Do something.
+   *   Operation response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<GetRegionOperationRequest, Operation> getCallable() {
+    return stub.getCallable();
+  }
+
+  @Override
+  public final void close() {
+    stub.close();
+  }
+
+  @Override
+  public void shutdown() {
+    stub.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return stub.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return stub.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    stub.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return stub.awaitTermination(duration, unit);
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsClientTest.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsClientTest.java
new file mode 100644
index 0000000000..7f6b78232a
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsClientTest.java
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1;
+
+import com.google.api.gax.core.NoCredentialsProvider;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.testing.MockHttpService;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ApiException;
+import com.google.api.gax.rpc.ApiExceptionFactory;
+import com.google.api.gax.rpc.InvalidArgumentException;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.testing.FakeStatusCode;
+import com.google.cloud.compute.v1.stub.HttpJsonRegionOperationsStub;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import javax.annotation.Generated;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+@Generated("by gapic-generator-java")
+public class RegionOperationsClientTest {
+  private static MockHttpService mockService;
+  private static RegionOperationsClient client;
+
+  @BeforeClass
+  public static void startStaticServer() throws IOException {
+    mockService =
+        new MockHttpService(
+            HttpJsonRegionOperationsStub.getMethodDescriptors(),
+            RegionOperationsSettings.getDefaultEndpoint());
+    RegionOperationsSettings settings =
+        RegionOperationsSettings.newBuilder()
+            .setTransportChannelProvider(
+                RegionOperationsSettings.defaultHttpJsonTransportProviderBuilder()
+                    .setHttpTransport(mockService)
+                    .build())
+            .setCredentialsProvider(NoCredentialsProvider.create())
+            .build();
+    client = RegionOperationsClient.create(settings);
+  }
+
+  @AfterClass
+  public static void stopServer() {
+    client.close();
+  }
+
+  @Before
+  public void setUp() {}
+
+  @After
+  public void tearDown() throws Exception {
+    mockService.reset();
+  }
+
+  @Test
+  public void getTest() throws Exception {
+    Operation expectedResponse =
+        Operation.newBuilder()
+            .setClientOperationId("clientOperationId-1230366697")
+            .setCreationTimestamp("creationTimestamp-370203401")
+            .setDescription("description-1724546052")
+            .setEndTime("endTime-1607243192")
+            .setError(Error.newBuilder().build())
+            .setHttpErrorMessage("httpErrorMessage1577303431")
+            .setHttpErrorStatusCode(1386087020)
+            .setId("id3355")
+            .setInsertTime("insertTime966165798")
+            .setKind("kind3292052")
+            .setName("name3373707")
+            .setOperationType("operationType91999553")
+            .setProgress(-1001078227)
+            .setRegion("region-934795532")
+            .setSelfLink("selfLink1191800166")
+            .setStartTime("startTime-2129294769")
+            .setStatusMessage("statusMessage-958704715")
+            .setTargetId("targetId-441951604")
+            .setTargetLink("targetLink486368555")
+            .setUser("user3599307")
+            .addAllWarnings(new ArrayList<Warnings>())
+            .setZone("zone3744684")
+            .build();
+    mockService.addResponse(expectedResponse);
+
+    String project = "project-309310695";
+    String region = "region-934795532";
+    String operation = "operation1662702951";
+
+    Operation actualResponse = client.get(project, region, operation);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<String> actualRequests = mockService.getRequestPaths();
+    Assert.assertEquals(1, actualRequests.size());
+
+    String apiClientHeaderKey =
+        mockService
+            .getRequestHeaders()
+            .get(ApiClientHeaderProvider.getDefaultApiClientHeaderKey())
+            .iterator()
+            .next();
+    Assert.assertTrue(
+        GaxHttpJsonProperties.getDefaultApiClientHeaderPattern()
+            .matcher(apiClientHeaderKey)
+            .matches());
+  }
+
+  @Test
+  public void getExceptionTest() throws Exception {
+    ApiException exception =
+        ApiExceptionFactory.createException(
+            new Exception(), FakeStatusCode.of(StatusCode.Code.INVALID_ARGUMENT), false);
+    mockService.addException(exception);
+
+    try {
+      String project = "project-309310695";
+      String region = "region-934795532";
+      String operation = "operation1662702951";
+      client.get(project, region, operation);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsSettings.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsSettings.java
new file mode 100644
index 0000000000..4e0ffca9d4
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/RegionOperationsSettings.java
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientSettings;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.cloud.compute.v1.stub.RegionOperationsStubSettings;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link RegionOperationsClient}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (compute.googleapis.com) and default port (443) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of get to 30 seconds:
+ *
+ * <pre>{@code
+ * RegionOperationsSettings.Builder regionOperationsSettingsBuilder =
+ *     RegionOperationsSettings.newBuilder();
+ * regionOperationsSettingsBuilder
+ *     .getSettings()
+ *     .setRetrySettings(
+ *         regionOperationsSettingsBuilder
+ *             .getSettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * RegionOperationsSettings regionOperationsSettings = regionOperationsSettingsBuilder.build();
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+public class RegionOperationsSettings extends ClientSettings<RegionOperationsSettings> {
+
+  /** Returns the object with the settings used for calls to get. */
+  public UnaryCallSettings<GetRegionOperationRequest, Operation> getSettings() {
+    return ((RegionOperationsStubSettings) getStubSettings()).getSettings();
+  }
+
+  public static final RegionOperationsSettings create(RegionOperationsStubSettings stub)
+      throws IOException {
+    return new RegionOperationsSettings.Builder(stub.toBuilder()).build();
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return RegionOperationsStubSettings.defaultExecutorProviderBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return RegionOperationsStubSettings.getDefaultEndpoint();
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return RegionOperationsStubSettings.getDefaultServiceScopes();
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return RegionOperationsStubSettings.defaultCredentialsProviderBuilder();
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return RegionOperationsStubSettings.defaultHttpJsonTransportProviderBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return RegionOperationsStubSettings.defaultTransportChannelProvider();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return RegionOperationsStubSettings.defaultApiClientHeaderProviderBuilder();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected RegionOperationsSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+  }
+
+  /** Builder for RegionOperationsSettings. */
+  public static class Builder extends ClientSettings.Builder<RegionOperationsSettings, Builder> {
+
+    protected Builder() throws IOException {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(RegionOperationsStubSettings.newBuilder(clientContext));
+    }
+
+    protected Builder(RegionOperationsSettings settings) {
+      super(settings.getStubSettings().toBuilder());
+    }
+
+    protected Builder(RegionOperationsStubSettings.Builder stubSettings) {
+      super(stubSettings);
+    }
+
+    private static Builder createDefault() {
+      return new Builder(RegionOperationsStubSettings.newBuilder());
+    }
+
+    public RegionOperationsStubSettings.Builder getStubSettingsBuilder() {
+      return ((RegionOperationsStubSettings.Builder) getStubSettings());
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(
+          getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
+      return this;
+    }
+
+    /** Returns the builder for the settings used for calls to get. */
+    public UnaryCallSettings.Builder<GetRegionOperationRequest, Operation> getSettings() {
+      return getStubSettingsBuilder().getSettings();
+    }
+
+    @Override
+    public RegionOperationsSettings build() throws IOException {
+      return new RegionOperationsSettings(this);
+    }
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/gapic_metadata.json b/test/integration/goldens/compute/com/google/cloud/compute/v1/gapic_metadata.json
new file mode 100644
index 0000000000..14eb0320fd
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/gapic_metadata.json
@@ -0,0 +1,42 @@
+{
+  "schema": "1.0",
+  "comment": "This file maps proto services/RPCs to the corresponding library clients/methods",
+  "language": "java",
+  "protoPackage": "google.cloud.compute.v1",
+  "libraryPackage": "com.google.cloud.compute.v1",
+  "services": {
+    "Addresses": {
+      "clients": {
+        "grpc": {
+          "libraryClient": "AddressesClient",
+          "rpcs": {
+            "AggregatedList": {
+              "methods": ["aggregatedList", "aggregatedList", "aggregatedListPagedCallable", "aggregatedListCallable"]
+            },
+            "Delete": {
+              "methods": ["delete", "delete", "deleteCallable"]
+            },
+            "Insert": {
+              "methods": ["insert", "insert", "insertCallable"]
+            },
+            "List": {
+              "methods": ["list", "list", "listPagedCallable", "listCallable"]
+            }
+          }
+        }
+      }
+    },
+    "RegionOperations": {
+      "clients": {
+        "grpc": {
+          "libraryClient": "RegionOperationsClient",
+          "rpcs": {
+            "Get": {
+              "methods": ["get", "get", "getCallable"]
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/package-info.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/package-info.java
new file mode 100644
index 0000000000..941f3ab751
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/package-info.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * The interfaces provided are listed below, along with usage samples.
+ *
+ * <p>======================= AddressesClient =======================
+ *
+ * <p>Service Description: Services
+ *
+ * <p>The Addresses API.
+ *
+ * <p>Sample for AddressesClient:
+ *
+ * <pre>{@code
+ * try (AddressesClient addressesClient = AddressesClient.create()) {
+ *   String project = "project-309310695";
+ *   String region = "region-934795532";
+ *   String address = "address-1147692044";
+ *   Operation response = addressesClient.delete(project, region, address);
+ * }
+ * }</pre>
+ *
+ * <p>======================= RegionOperationsClient =======================
+ *
+ * <p>Service Description: The RegionOperations API.
+ *
+ * <p>Sample for RegionOperationsClient:
+ *
+ * <pre>{@code
+ * try (RegionOperationsClient regionOperationsClient = RegionOperationsClient.create()) {
+ *   String project = "project-309310695";
+ *   String region = "region-934795532";
+ *   String operation = "operation1662702951";
+ *   Operation response = regionOperationsClient.get(project, region, operation);
+ * }
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+package com.google.cloud.compute.v1;
+
+import javax.annotation.Generated;
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/AddressesStub.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/AddressesStub.java
new file mode 100644
index 0000000000..b7d7f6e590
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/AddressesStub.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import static com.google.cloud.compute.v1.AddressesClient.AggregatedListPagedResponse;
+import static com.google.cloud.compute.v1.AddressesClient.ListPagedResponse;
+
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.AddressAggregatedList;
+import com.google.cloud.compute.v1.AddressList;
+import com.google.cloud.compute.v1.AggregatedListAddressesRequest;
+import com.google.cloud.compute.v1.DeleteAddressRequest;
+import com.google.cloud.compute.v1.InsertAddressRequest;
+import com.google.cloud.compute.v1.ListAddressesRequest;
+import com.google.cloud.compute.v1.Operation;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Base stub class for the Addresses service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@Generated("by gapic-generator-java")
+public abstract class AddressesStub implements BackgroundResource {
+
+  public UnaryCallable<AggregatedListAddressesRequest, AggregatedListPagedResponse>
+      aggregatedListPagedCallable() {
+    throw new UnsupportedOperationException("Not implemented: aggregatedListPagedCallable()");
+  }
+
+  public UnaryCallable<AggregatedListAddressesRequest, AddressAggregatedList>
+      aggregatedListCallable() {
+    throw new UnsupportedOperationException("Not implemented: aggregatedListCallable()");
+  }
+
+  public UnaryCallable<DeleteAddressRequest, Operation> deleteCallable() {
+    throw new UnsupportedOperationException("Not implemented: deleteCallable()");
+  }
+
+  public UnaryCallable<InsertAddressRequest, Operation> insertCallable() {
+    throw new UnsupportedOperationException("Not implemented: insertCallable()");
+  }
+
+  public UnaryCallable<ListAddressesRequest, ListPagedResponse> listPagedCallable() {
+    throw new UnsupportedOperationException("Not implemented: listPagedCallable()");
+  }
+
+  public UnaryCallable<ListAddressesRequest, AddressList> listCallable() {
+    throw new UnsupportedOperationException("Not implemented: listCallable()");
+  }
+
+  @Override
+  public abstract void close();
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/AddressesStubSettings.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/AddressesStubSettings.java
new file mode 100644
index 0000000000..69e3c4d6c0
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/AddressesStubSettings.java
@@ -0,0 +1,500 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import static com.google.cloud.compute.v1.AddressesClient.AggregatedListPagedResponse;
+import static com.google.cloud.compute.v1.AddressesClient.ListPagedResponse;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.ApiFuture;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GaxProperties;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.retrying.RetrySettings;
+import com.google.api.gax.rpc.ApiCallContext;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.PageContext;
+import com.google.api.gax.rpc.PagedCallSettings;
+import com.google.api.gax.rpc.PagedListDescriptor;
+import com.google.api.gax.rpc.PagedListResponseFactory;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.Address;
+import com.google.cloud.compute.v1.AddressAggregatedList;
+import com.google.cloud.compute.v1.AddressList;
+import com.google.cloud.compute.v1.AddressesScopedList;
+import com.google.cloud.compute.v1.AggregatedListAddressesRequest;
+import com.google.cloud.compute.v1.DeleteAddressRequest;
+import com.google.cloud.compute.v1.InsertAddressRequest;
+import com.google.cloud.compute.v1.ListAddressesRequest;
+import com.google.cloud.compute.v1.Operation;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import javax.annotation.Generated;
+import org.threeten.bp.Duration;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link AddressesStub}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (compute.googleapis.com) and default port (443) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of delete to 30 seconds:
+ *
+ * <pre>{@code
+ * AddressesStubSettings.Builder addressesSettingsBuilder = AddressesStubSettings.newBuilder();
+ * addressesSettingsBuilder
+ *     .deleteSettings()
+ *     .setRetrySettings(
+ *         addressesSettingsBuilder
+ *             .deleteSettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * AddressesStubSettings addressesSettings = addressesSettingsBuilder.build();
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+public class AddressesStubSettings extends StubSettings<AddressesStubSettings> {
+  /** The default scopes of the service. */
+  private static final ImmutableList<String> DEFAULT_SERVICE_SCOPES =
+      ImmutableList.<String>builder()
+          .add("https://www.googleapis.com/auth/compute")
+          .add("https://www.googleapis.com/auth/cloud-platform")
+          .build();
+
+  private final PagedCallSettings<
+          AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+      aggregatedListSettings;
+  private final UnaryCallSettings<DeleteAddressRequest, Operation> deleteSettings;
+  private final UnaryCallSettings<InsertAddressRequest, Operation> insertSettings;
+  private final PagedCallSettings<ListAddressesRequest, AddressList, ListPagedResponse>
+      listSettings;
+
+  private static final PagedListDescriptor<
+          AggregatedListAddressesRequest,
+          AddressAggregatedList,
+          Map.Entry<String, AddressesScopedList>>
+      AGGREGATED_LIST_PAGE_STR_DESC =
+          new PagedListDescriptor<
+              AggregatedListAddressesRequest,
+              AddressAggregatedList,
+              Map.Entry<String, AddressesScopedList>>() {
+            @Override
+            public String emptyToken() {
+              return "";
+            }
+
+            @Override
+            public AggregatedListAddressesRequest injectToken(
+                AggregatedListAddressesRequest payload, String token) {
+              return AggregatedListAddressesRequest.newBuilder(payload).setPageToken(token).build();
+            }
+
+            @Override
+            public AggregatedListAddressesRequest injectPageSize(
+                AggregatedListAddressesRequest payload, int pageSize) {
+              return AggregatedListAddressesRequest.newBuilder(payload)
+                  .setMaxResults(pageSize)
+                  .build();
+            }
+
+            @Override
+            public Integer extractPageSize(AggregatedListAddressesRequest payload) {
+              return payload.getMaxResults();
+            }
+
+            @Override
+            public String extractNextToken(AddressAggregatedList payload) {
+              return payload.getNextPageToken();
+            }
+
+            @Override
+            public Iterable<Map.Entry<String, AddressesScopedList>> extractResources(
+                AddressAggregatedList payload) {
+              return payload.getItemsMap() == null
+                  ? Collections.<Map.Entry<String, AddressesScopedList>>emptySet()
+                  : payload.getItemsMap().entrySet();
+            }
+          };
+
+  private static final PagedListDescriptor<ListAddressesRequest, AddressList, Address>
+      LIST_PAGE_STR_DESC =
+          new PagedListDescriptor<ListAddressesRequest, AddressList, Address>() {
+            @Override
+            public String emptyToken() {
+              return "";
+            }
+
+            @Override
+            public ListAddressesRequest injectToken(ListAddressesRequest payload, String token) {
+              return ListAddressesRequest.newBuilder(payload).setPageToken(token).build();
+            }
+
+            @Override
+            public ListAddressesRequest injectPageSize(ListAddressesRequest payload, int pageSize) {
+              return ListAddressesRequest.newBuilder(payload).setMaxResults(pageSize).build();
+            }
+
+            @Override
+            public Integer extractPageSize(ListAddressesRequest payload) {
+              return payload.getMaxResults();
+            }
+
+            @Override
+            public String extractNextToken(AddressList payload) {
+              return payload.getNextPageToken();
+            }
+
+            @Override
+            public Iterable<Address> extractResources(AddressList payload) {
+              return payload.getItemsList() == null
+                  ? ImmutableList.<Address>of()
+                  : payload.getItemsList();
+            }
+          };
+
+  private static final PagedListResponseFactory<
+          AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+      AGGREGATED_LIST_PAGE_STR_FACT =
+          new PagedListResponseFactory<
+              AggregatedListAddressesRequest,
+              AddressAggregatedList,
+              AggregatedListPagedResponse>() {
+            @Override
+            public ApiFuture<AggregatedListPagedResponse> getFuturePagedResponse(
+                UnaryCallable<AggregatedListAddressesRequest, AddressAggregatedList> callable,
+                AggregatedListAddressesRequest request,
+                ApiCallContext context,
+                ApiFuture<AddressAggregatedList> futureResponse) {
+              PageContext<
+                      AggregatedListAddressesRequest,
+                      AddressAggregatedList,
+                      Map.Entry<String, AddressesScopedList>>
+                  pageContext =
+                      PageContext.create(callable, AGGREGATED_LIST_PAGE_STR_DESC, request, context);
+              return AggregatedListPagedResponse.createAsync(pageContext, futureResponse);
+            }
+          };
+
+  private static final PagedListResponseFactory<
+          ListAddressesRequest, AddressList, ListPagedResponse>
+      LIST_PAGE_STR_FACT =
+          new PagedListResponseFactory<ListAddressesRequest, AddressList, ListPagedResponse>() {
+            @Override
+            public ApiFuture<ListPagedResponse> getFuturePagedResponse(
+                UnaryCallable<ListAddressesRequest, AddressList> callable,
+                ListAddressesRequest request,
+                ApiCallContext context,
+                ApiFuture<AddressList> futureResponse) {
+              PageContext<ListAddressesRequest, AddressList, Address> pageContext =
+                  PageContext.create(callable, LIST_PAGE_STR_DESC, request, context);
+              return ListPagedResponse.createAsync(pageContext, futureResponse);
+            }
+          };
+
+  /** Returns the object with the settings used for calls to aggregatedList. */
+  public PagedCallSettings<
+          AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+      aggregatedListSettings() {
+    return aggregatedListSettings;
+  }
+
+  /** Returns the object with the settings used for calls to delete. */
+  public UnaryCallSettings<DeleteAddressRequest, Operation> deleteSettings() {
+    return deleteSettings;
+  }
+
+  /** Returns the object with the settings used for calls to insert. */
+  public UnaryCallSettings<InsertAddressRequest, Operation> insertSettings() {
+    return insertSettings;
+  }
+
+  /** Returns the object with the settings used for calls to list. */
+  public PagedCallSettings<ListAddressesRequest, AddressList, ListPagedResponse> listSettings() {
+    return listSettings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public AddressesStub createStub() throws IOException {
+    if (getTransportChannelProvider()
+        .getTransportName()
+        .equals(HttpJsonTransportChannel.getHttpJsonTransportName())) {
+      return HttpJsonAddressesStub.create(this);
+    }
+    throw new UnsupportedOperationException(
+        String.format(
+            "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return InstantiatingExecutorProvider.newBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return "compute.googleapis.com:443";
+  }
+
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "compute.mtls.googleapis.com:443";
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return DEFAULT_SERVICE_SCOPES;
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return InstantiatingHttpJsonChannelProvider.newBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return defaultHttpJsonTransportProviderBuilder().build();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return ApiClientHeaderProvider.newBuilder()
+        .setGeneratedLibToken("gapic", GaxProperties.getLibraryVersion(AddressesStubSettings.class))
+        .setTransportToken(
+            GaxHttpJsonProperties.getHttpJsonTokenName(),
+            GaxHttpJsonProperties.getHttpJsonVersion());
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected AddressesStubSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+
+    aggregatedListSettings = settingsBuilder.aggregatedListSettings().build();
+    deleteSettings = settingsBuilder.deleteSettings().build();
+    insertSettings = settingsBuilder.insertSettings().build();
+    listSettings = settingsBuilder.listSettings().build();
+  }
+
+  /** Builder for AddressesStubSettings. */
+  public static class Builder extends StubSettings.Builder<AddressesStubSettings, Builder> {
+    private final ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders;
+    private final PagedCallSettings.Builder<
+            AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+        aggregatedListSettings;
+    private final UnaryCallSettings.Builder<DeleteAddressRequest, Operation> deleteSettings;
+    private final UnaryCallSettings.Builder<InsertAddressRequest, Operation> insertSettings;
+    private final PagedCallSettings.Builder<ListAddressesRequest, AddressList, ListPagedResponse>
+        listSettings;
+    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
+        RETRYABLE_CODE_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
+          ImmutableMap.builder();
+      definitions.put(
+          "retry_policy_0_codes",
+          ImmutableSet.copyOf(
+              Lists.<StatusCode.Code>newArrayList(
+                  StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
+      definitions.put(
+          "no_retry_1_codes", ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList()));
+      RETRYABLE_CODE_DEFINITIONS = definitions.build();
+    }
+
+    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
+      RetrySettings settings = null;
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRetryDelay(Duration.ofMillis(100L))
+              .setRetryDelayMultiplier(1.3)
+              .setMaxRetryDelay(Duration.ofMillis(60000L))
+              .setInitialRpcTimeout(Duration.ofMillis(600000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(600000L))
+              .setTotalTimeout(Duration.ofMillis(600000L))
+              .build();
+      definitions.put("retry_policy_0_params", settings);
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRpcTimeout(Duration.ofMillis(600000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(600000L))
+              .setTotalTimeout(Duration.ofMillis(600000L))
+              .build();
+      definitions.put("no_retry_1_params", settings);
+      RETRY_PARAM_DEFINITIONS = definitions.build();
+    }
+
+    protected Builder() {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(clientContext);
+
+      aggregatedListSettings = PagedCallSettings.newBuilder(AGGREGATED_LIST_PAGE_STR_FACT);
+      deleteSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      insertSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      listSettings = PagedCallSettings.newBuilder(LIST_PAGE_STR_FACT);
+
+      unaryMethodSettingsBuilders =
+          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
+              aggregatedListSettings, deleteSettings, insertSettings, listSettings);
+      initDefaults(this);
+    }
+
+    protected Builder(AddressesStubSettings settings) {
+      super(settings);
+
+      aggregatedListSettings = settings.aggregatedListSettings.toBuilder();
+      deleteSettings = settings.deleteSettings.toBuilder();
+      insertSettings = settings.insertSettings.toBuilder();
+      listSettings = settings.listSettings.toBuilder();
+
+      unaryMethodSettingsBuilders =
+          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
+              aggregatedListSettings, deleteSettings, insertSettings, listSettings);
+    }
+
+    private static Builder createDefault() {
+      Builder builder = new Builder(((ClientContext) null));
+
+      builder.setTransportChannelProvider(defaultTransportChannelProvider());
+      builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
+      builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
+      builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
+
+      return initDefaults(builder);
+    }
+
+    private static Builder initDefaults(Builder builder) {
+      builder
+          .aggregatedListSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
+
+      builder
+          .deleteSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_1_params"));
+
+      builder
+          .insertSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_1_params"));
+
+      builder
+          .listSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
+
+      return builder;
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
+      return this;
+    }
+
+    public ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders() {
+      return unaryMethodSettingsBuilders;
+    }
+
+    /** Returns the builder for the settings used for calls to aggregatedList. */
+    public PagedCallSettings.Builder<
+            AggregatedListAddressesRequest, AddressAggregatedList, AggregatedListPagedResponse>
+        aggregatedListSettings() {
+      return aggregatedListSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to delete. */
+    public UnaryCallSettings.Builder<DeleteAddressRequest, Operation> deleteSettings() {
+      return deleteSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to insert. */
+    public UnaryCallSettings.Builder<InsertAddressRequest, Operation> insertSettings() {
+      return insertSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to list. */
+    public PagedCallSettings.Builder<ListAddressesRequest, AddressList, ListPagedResponse>
+        listSettings() {
+      return listSettings;
+    }
+
+    @Override
+    public AddressesStubSettings build() throws IOException {
+      return new AddressesStubSettings(this);
+    }
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonAddressesCallableFactory.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonAddressesCallableFactory.java
new file mode 100644
index 0000000000..afa275a6f5
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonAddressesCallableFactory.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.httpjson.ApiMessage;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonCallableFactory;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.rpc.BatchingCallSettings;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.OperationCallSettings;
+import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.PagedCallSettings;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.api.gax.rpc.UnaryCallable;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * REST callable factory implementation for the Addresses service API.
+ *
+ * <p>This class is for advanced usage.
+ */
+@Generated("by gapic-generator-java")
+@BetaApi
+public class HttpJsonAddressesCallableFactory
+    implements HttpJsonStubCallableFactory<ApiMessage, BackgroundResource> {
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
+      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+      UnaryCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return HttpJsonCallableFactory.createUnaryCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT, PagedListResponseT>
+      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
+          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> callSettings,
+          ClientContext clientContext) {
+    return HttpJsonCallableFactory.createPagedCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
+      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+      BatchingCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return HttpJsonCallableFactory.createBatchingCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @BetaApi(
+      "The surface for long-running operations is not stable yet and may change in the future.")
+  @Override
+  public <RequestT, ResponseT, MetadataT>
+      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
+          HttpJsonCallSettings<RequestT, ApiMessage> httpJsonCallSettings,
+          OperationCallSettings<RequestT, ResponseT, MetadataT> callSettings,
+          ClientContext clientContext,
+          BackgroundResource operationsStub) {
+    return null;
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonAddressesStub.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonAddressesStub.java
new file mode 100644
index 0000000000..d8d960d342
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonAddressesStub.java
@@ -0,0 +1,387 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import static com.google.cloud.compute.v1.AddressesClient.AggregatedListPagedResponse;
+import static com.google.cloud.compute.v1.AddressesClient.ListPagedResponse;
+
+import com.google.api.client.http.HttpMethods;
+import com.google.api.core.BetaApi;
+import com.google.api.core.InternalApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.core.BackgroundResourceAggregation;
+import com.google.api.gax.httpjson.ApiMethodDescriptor;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.httpjson.ProtoMessageRequestFormatter;
+import com.google.api.gax.httpjson.ProtoMessageResponseParser;
+import com.google.api.gax.httpjson.ProtoRestSerializer;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.AddressAggregatedList;
+import com.google.cloud.compute.v1.AddressList;
+import com.google.cloud.compute.v1.AggregatedListAddressesRequest;
+import com.google.cloud.compute.v1.DeleteAddressRequest;
+import com.google.cloud.compute.v1.InsertAddressRequest;
+import com.google.cloud.compute.v1.ListAddressesRequest;
+import com.google.cloud.compute.v1.Operation;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * REST stub implementation for the Addresses service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@Generated("by gapic-generator-java")
+@BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+public class HttpJsonAddressesStub extends AddressesStub {
+  private static final ApiMethodDescriptor<AggregatedListAddressesRequest, AddressAggregatedList>
+      aggregatedListMethodDescriptor =
+          ApiMethodDescriptor.<AggregatedListAddressesRequest, AddressAggregatedList>newBuilder()
+              .setFullMethodName("google.cloud.compute.v1.Addresses/AggregatedList")
+              .setHttpMethod(HttpMethods.GET)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<AggregatedListAddressesRequest>newBuilder()
+                      .setPath(
+                          "/compute/v1/projects/{project}/aggregated/addresses",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<AggregatedListAddressesRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putPathParam(fields, "project", request.getProject());
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<AggregatedListAddressesRequest> serializer =
+                                ProtoRestSerializer.create();
+                            if (request.hasFilter()) {
+                              serializer.putQueryParam(fields, "filter", request.getFilter());
+                            }
+                            if (request.hasIncludeAllScopes()) {
+                              serializer.putQueryParam(
+                                  fields, "includeAllScopes", request.getIncludeAllScopes());
+                            }
+                            if (request.hasMaxResults()) {
+                              serializer.putQueryParam(
+                                  fields, "maxResults", request.getMaxResults());
+                            }
+                            if (request.hasOrderBy()) {
+                              serializer.putQueryParam(fields, "orderBy", request.getOrderBy());
+                            }
+                            if (request.hasPageToken()) {
+                              serializer.putQueryParam(fields, "pageToken", request.getPageToken());
+                            }
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(request -> null)
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<AddressAggregatedList>newBuilder()
+                      .setDefaultInstance(AddressAggregatedList.getDefaultInstance())
+                      .build())
+              .build();
+
+  private static final ApiMethodDescriptor<DeleteAddressRequest, Operation> deleteMethodDescriptor =
+      ApiMethodDescriptor.<DeleteAddressRequest, Operation>newBuilder()
+          .setFullMethodName("google.cloud.compute.v1.Addresses/Delete")
+          .setHttpMethod(HttpMethods.DELETE)
+          .setRequestFormatter(
+              ProtoMessageRequestFormatter.<DeleteAddressRequest>newBuilder()
+                  .setPath(
+                      "/compute/v1/projects/{project}/regions/{region}/addresses/{address}",
+                      request -> {
+                        Map<String, String> fields = new HashMap<>();
+                        ProtoRestSerializer<DeleteAddressRequest> serializer =
+                            ProtoRestSerializer.create();
+                        serializer.putPathParam(fields, "address", request.getAddress());
+                        serializer.putPathParam(fields, "project", request.getProject());
+                        serializer.putPathParam(fields, "region", request.getRegion());
+                        return fields;
+                      })
+                  .setQueryParamsExtractor(
+                      request -> {
+                        Map<String, List<String>> fields = new HashMap<>();
+                        ProtoRestSerializer<DeleteAddressRequest> serializer =
+                            ProtoRestSerializer.create();
+                        if (request.hasRequestId()) {
+                          serializer.putQueryParam(fields, "requestId", request.getRequestId());
+                        }
+                        return fields;
+                      })
+                  .setRequestBodyExtractor(request -> null)
+                  .build())
+          .setResponseParser(
+              ProtoMessageResponseParser.<Operation>newBuilder()
+                  .setDefaultInstance(Operation.getDefaultInstance())
+                  .build())
+          .build();
+
+  private static final ApiMethodDescriptor<InsertAddressRequest, Operation> insertMethodDescriptor =
+      ApiMethodDescriptor.<InsertAddressRequest, Operation>newBuilder()
+          .setFullMethodName("google.cloud.compute.v1.Addresses/Insert")
+          .setHttpMethod(HttpMethods.POST)
+          .setRequestFormatter(
+              ProtoMessageRequestFormatter.<InsertAddressRequest>newBuilder()
+                  .setPath(
+                      "/compute/v1/projects/{project}/regions/{region}/addresses",
+                      request -> {
+                        Map<String, String> fields = new HashMap<>();
+                        ProtoRestSerializer<InsertAddressRequest> serializer =
+                            ProtoRestSerializer.create();
+                        serializer.putPathParam(fields, "project", request.getProject());
+                        serializer.putPathParam(fields, "region", request.getRegion());
+                        return fields;
+                      })
+                  .setQueryParamsExtractor(
+                      request -> {
+                        Map<String, List<String>> fields = new HashMap<>();
+                        ProtoRestSerializer<InsertAddressRequest> serializer =
+                            ProtoRestSerializer.create();
+                        if (request.hasRequestId()) {
+                          serializer.putQueryParam(fields, "requestId", request.getRequestId());
+                        }
+                        return fields;
+                      })
+                  .setRequestBodyExtractor(
+                      request ->
+                          ProtoRestSerializer.create()
+                              .toBody("addressResource", request.getAddressResource()))
+                  .build())
+          .setResponseParser(
+              ProtoMessageResponseParser.<Operation>newBuilder()
+                  .setDefaultInstance(Operation.getDefaultInstance())
+                  .build())
+          .build();
+
+  private static final ApiMethodDescriptor<ListAddressesRequest, AddressList> listMethodDescriptor =
+      ApiMethodDescriptor.<ListAddressesRequest, AddressList>newBuilder()
+          .setFullMethodName("google.cloud.compute.v1.Addresses/List")
+          .setHttpMethod(HttpMethods.GET)
+          .setRequestFormatter(
+              ProtoMessageRequestFormatter.<ListAddressesRequest>newBuilder()
+                  .setPath(
+                      "/compute/v1/projects/{project}/regions/{region}/addresses",
+                      request -> {
+                        Map<String, String> fields = new HashMap<>();
+                        ProtoRestSerializer<ListAddressesRequest> serializer =
+                            ProtoRestSerializer.create();
+                        serializer.putPathParam(fields, "project", request.getProject());
+                        serializer.putPathParam(fields, "region", request.getRegion());
+                        return fields;
+                      })
+                  .setQueryParamsExtractor(
+                      request -> {
+                        Map<String, List<String>> fields = new HashMap<>();
+                        ProtoRestSerializer<ListAddressesRequest> serializer =
+                            ProtoRestSerializer.create();
+                        if (request.hasFilter()) {
+                          serializer.putQueryParam(fields, "filter", request.getFilter());
+                        }
+                        if (request.hasMaxResults()) {
+                          serializer.putQueryParam(fields, "maxResults", request.getMaxResults());
+                        }
+                        serializer.putQueryParam(fields, "orderBy", request.getOrderBy());
+                        if (request.hasPageToken()) {
+                          serializer.putQueryParam(fields, "pageToken", request.getPageToken());
+                        }
+                        return fields;
+                      })
+                  .setRequestBodyExtractor(request -> null)
+                  .build())
+          .setResponseParser(
+              ProtoMessageResponseParser.<AddressList>newBuilder()
+                  .setDefaultInstance(AddressList.getDefaultInstance())
+                  .build())
+          .build();
+
+  private final UnaryCallable<AggregatedListAddressesRequest, AddressAggregatedList>
+      aggregatedListCallable;
+  private final UnaryCallable<AggregatedListAddressesRequest, AggregatedListPagedResponse>
+      aggregatedListPagedCallable;
+  private final UnaryCallable<DeleteAddressRequest, Operation> deleteCallable;
+  private final UnaryCallable<InsertAddressRequest, Operation> insertCallable;
+  private final UnaryCallable<ListAddressesRequest, AddressList> listCallable;
+  private final UnaryCallable<ListAddressesRequest, ListPagedResponse> listPagedCallable;
+
+  private final BackgroundResource backgroundResources;
+  private final HttpJsonStubCallableFactory callableFactory;
+
+  public static final HttpJsonAddressesStub create(AddressesStubSettings settings)
+      throws IOException {
+    return new HttpJsonAddressesStub(settings, ClientContext.create(settings));
+  }
+
+  public static final HttpJsonAddressesStub create(ClientContext clientContext) throws IOException {
+    return new HttpJsonAddressesStub(AddressesStubSettings.newBuilder().build(), clientContext);
+  }
+
+  public static final HttpJsonAddressesStub create(
+      ClientContext clientContext, HttpJsonStubCallableFactory callableFactory) throws IOException {
+    return new HttpJsonAddressesStub(
+        AddressesStubSettings.newBuilder().build(), clientContext, callableFactory);
+  }
+
+  /**
+   * Constructs an instance of HttpJsonAddressesStub, using the given settings. This is protected so
+   * that it is easy to make a subclass, but otherwise, the static factory methods should be
+   * preferred.
+   */
+  protected HttpJsonAddressesStub(AddressesStubSettings settings, ClientContext clientContext)
+      throws IOException {
+    this(settings, clientContext, new HttpJsonAddressesCallableFactory());
+  }
+
+  /**
+   * Constructs an instance of HttpJsonAddressesStub, using the given settings. This is protected so
+   * that it is easy to make a subclass, but otherwise, the static factory methods should be
+   * preferred.
+   */
+  protected HttpJsonAddressesStub(
+      AddressesStubSettings settings,
+      ClientContext clientContext,
+      HttpJsonStubCallableFactory callableFactory)
+      throws IOException {
+    this.callableFactory = callableFactory;
+
+    HttpJsonCallSettings<AggregatedListAddressesRequest, AddressAggregatedList>
+        aggregatedListTransportSettings =
+            HttpJsonCallSettings.<AggregatedListAddressesRequest, AddressAggregatedList>newBuilder()
+                .setMethodDescriptor(aggregatedListMethodDescriptor)
+                .build();
+    HttpJsonCallSettings<DeleteAddressRequest, Operation> deleteTransportSettings =
+        HttpJsonCallSettings.<DeleteAddressRequest, Operation>newBuilder()
+            .setMethodDescriptor(deleteMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<InsertAddressRequest, Operation> insertTransportSettings =
+        HttpJsonCallSettings.<InsertAddressRequest, Operation>newBuilder()
+            .setMethodDescriptor(insertMethodDescriptor)
+            .build();
+    HttpJsonCallSettings<ListAddressesRequest, AddressList> listTransportSettings =
+        HttpJsonCallSettings.<ListAddressesRequest, AddressList>newBuilder()
+            .setMethodDescriptor(listMethodDescriptor)
+            .build();
+
+    this.aggregatedListCallable =
+        callableFactory.createUnaryCallable(
+            aggregatedListTransportSettings, settings.aggregatedListSettings(), clientContext);
+    this.aggregatedListPagedCallable =
+        callableFactory.createPagedCallable(
+            aggregatedListTransportSettings, settings.aggregatedListSettings(), clientContext);
+    this.deleteCallable =
+        callableFactory.createUnaryCallable(
+            deleteTransportSettings, settings.deleteSettings(), clientContext);
+    this.insertCallable =
+        callableFactory.createUnaryCallable(
+            insertTransportSettings, settings.insertSettings(), clientContext);
+    this.listCallable =
+        callableFactory.createUnaryCallable(
+            listTransportSettings, settings.listSettings(), clientContext);
+    this.listPagedCallable =
+        callableFactory.createPagedCallable(
+            listTransportSettings, settings.listSettings(), clientContext);
+
+    this.backgroundResources =
+        new BackgroundResourceAggregation(clientContext.getBackgroundResources());
+  }
+
+  @InternalApi
+  public static List<ApiMethodDescriptor> getMethodDescriptors() {
+    List<ApiMethodDescriptor> methodDescriptors = new ArrayList<>();
+    methodDescriptors.add(aggregatedListMethodDescriptor);
+    methodDescriptors.add(deleteMethodDescriptor);
+    methodDescriptors.add(insertMethodDescriptor);
+    methodDescriptors.add(listMethodDescriptor);
+    return methodDescriptors;
+  }
+
+  @Override
+  public UnaryCallable<AggregatedListAddressesRequest, AddressAggregatedList>
+      aggregatedListCallable() {
+    return aggregatedListCallable;
+  }
+
+  @Override
+  public UnaryCallable<AggregatedListAddressesRequest, AggregatedListPagedResponse>
+      aggregatedListPagedCallable() {
+    return aggregatedListPagedCallable;
+  }
+
+  @Override
+  public UnaryCallable<DeleteAddressRequest, Operation> deleteCallable() {
+    return deleteCallable;
+  }
+
+  @Override
+  public UnaryCallable<InsertAddressRequest, Operation> insertCallable() {
+    return insertCallable;
+  }
+
+  @Override
+  public UnaryCallable<ListAddressesRequest, AddressList> listCallable() {
+    return listCallable;
+  }
+
+  @Override
+  public UnaryCallable<ListAddressesRequest, ListPagedResponse> listPagedCallable() {
+    return listPagedCallable;
+  }
+
+  @Override
+  public final void close() {
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
+  }
+
+  @Override
+  public void shutdown() {
+    backgroundResources.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return backgroundResources.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return backgroundResources.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    backgroundResources.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return backgroundResources.awaitTermination(duration, unit);
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonRegionOperationsCallableFactory.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonRegionOperationsCallableFactory.java
new file mode 100644
index 0000000000..6dac14a84e
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonRegionOperationsCallableFactory.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.httpjson.ApiMessage;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonCallableFactory;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.rpc.BatchingCallSettings;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.OperationCallSettings;
+import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.PagedCallSettings;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.api.gax.rpc.UnaryCallable;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * REST callable factory implementation for the RegionOperations service API.
+ *
+ * <p>This class is for advanced usage.
+ */
+@Generated("by gapic-generator-java")
+@BetaApi
+public class HttpJsonRegionOperationsCallableFactory
+    implements HttpJsonStubCallableFactory<ApiMessage, BackgroundResource> {
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
+      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+      UnaryCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return HttpJsonCallableFactory.createUnaryCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT, PagedListResponseT>
+      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
+          HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> callSettings,
+          ClientContext clientContext) {
+    return HttpJsonCallableFactory.createPagedCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
+      HttpJsonCallSettings<RequestT, ResponseT> httpJsonCallSettings,
+      BatchingCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return HttpJsonCallableFactory.createBatchingCallable(
+        httpJsonCallSettings, callSettings, clientContext);
+  }
+
+  @BetaApi(
+      "The surface for long-running operations is not stable yet and may change in the future.")
+  @Override
+  public <RequestT, ResponseT, MetadataT>
+      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
+          HttpJsonCallSettings<RequestT, ApiMessage> httpJsonCallSettings,
+          OperationCallSettings<RequestT, ResponseT, MetadataT> callSettings,
+          ClientContext clientContext,
+          BackgroundResource operationsStub) {
+    return null;
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonRegionOperationsStub.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonRegionOperationsStub.java
new file mode 100644
index 0000000000..9d90915792
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/HttpJsonRegionOperationsStub.java
@@ -0,0 +1,188 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import com.google.api.client.http.HttpMethods;
+import com.google.api.core.BetaApi;
+import com.google.api.core.InternalApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.core.BackgroundResourceAggregation;
+import com.google.api.gax.httpjson.ApiMethodDescriptor;
+import com.google.api.gax.httpjson.HttpJsonCallSettings;
+import com.google.api.gax.httpjson.HttpJsonStubCallableFactory;
+import com.google.api.gax.httpjson.ProtoMessageRequestFormatter;
+import com.google.api.gax.httpjson.ProtoMessageResponseParser;
+import com.google.api.gax.httpjson.ProtoRestSerializer;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.GetRegionOperationRequest;
+import com.google.cloud.compute.v1.Operation;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * REST stub implementation for the RegionOperations service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@Generated("by gapic-generator-java")
+@BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+public class HttpJsonRegionOperationsStub extends RegionOperationsStub {
+  private static final ApiMethodDescriptor<GetRegionOperationRequest, Operation>
+      getMethodDescriptor =
+          ApiMethodDescriptor.<GetRegionOperationRequest, Operation>newBuilder()
+              .setFullMethodName("google.cloud.compute.v1.RegionOperations/Get")
+              .setHttpMethod(HttpMethods.GET)
+              .setRequestFormatter(
+                  ProtoMessageRequestFormatter.<GetRegionOperationRequest>newBuilder()
+                      .setPath(
+                          "/compute/v1/projects/{project}/regions/{region}/operations/{operation}",
+                          request -> {
+                            Map<String, String> fields = new HashMap<>();
+                            ProtoRestSerializer<GetRegionOperationRequest> serializer =
+                                ProtoRestSerializer.create();
+                            serializer.putPathParam(fields, "operation", request.getOperation());
+                            serializer.putPathParam(fields, "project", request.getProject());
+                            serializer.putPathParam(fields, "region", request.getRegion());
+                            return fields;
+                          })
+                      .setQueryParamsExtractor(
+                          request -> {
+                            Map<String, List<String>> fields = new HashMap<>();
+                            ProtoRestSerializer<GetRegionOperationRequest> serializer =
+                                ProtoRestSerializer.create();
+                            return fields;
+                          })
+                      .setRequestBodyExtractor(request -> null)
+                      .build())
+              .setResponseParser(
+                  ProtoMessageResponseParser.<Operation>newBuilder()
+                      .setDefaultInstance(Operation.getDefaultInstance())
+                      .build())
+              .build();
+
+  private final UnaryCallable<GetRegionOperationRequest, Operation> getCallable;
+
+  private final BackgroundResource backgroundResources;
+  private final HttpJsonStubCallableFactory callableFactory;
+
+  public static final HttpJsonRegionOperationsStub create(RegionOperationsStubSettings settings)
+      throws IOException {
+    return new HttpJsonRegionOperationsStub(settings, ClientContext.create(settings));
+  }
+
+  public static final HttpJsonRegionOperationsStub create(ClientContext clientContext)
+      throws IOException {
+    return new HttpJsonRegionOperationsStub(
+        RegionOperationsStubSettings.newBuilder().build(), clientContext);
+  }
+
+  public static final HttpJsonRegionOperationsStub create(
+      ClientContext clientContext, HttpJsonStubCallableFactory callableFactory) throws IOException {
+    return new HttpJsonRegionOperationsStub(
+        RegionOperationsStubSettings.newBuilder().build(), clientContext, callableFactory);
+  }
+
+  /**
+   * Constructs an instance of HttpJsonRegionOperationsStub, using the given settings. This is
+   * protected so that it is easy to make a subclass, but otherwise, the static factory methods
+   * should be preferred.
+   */
+  protected HttpJsonRegionOperationsStub(
+      RegionOperationsStubSettings settings, ClientContext clientContext) throws IOException {
+    this(settings, clientContext, new HttpJsonRegionOperationsCallableFactory());
+  }
+
+  /**
+   * Constructs an instance of HttpJsonRegionOperationsStub, using the given settings. This is
+   * protected so that it is easy to make a subclass, but otherwise, the static factory methods
+   * should be preferred.
+   */
+  protected HttpJsonRegionOperationsStub(
+      RegionOperationsStubSettings settings,
+      ClientContext clientContext,
+      HttpJsonStubCallableFactory callableFactory)
+      throws IOException {
+    this.callableFactory = callableFactory;
+
+    HttpJsonCallSettings<GetRegionOperationRequest, Operation> getTransportSettings =
+        HttpJsonCallSettings.<GetRegionOperationRequest, Operation>newBuilder()
+            .setMethodDescriptor(getMethodDescriptor)
+            .build();
+
+    this.getCallable =
+        callableFactory.createUnaryCallable(
+            getTransportSettings, settings.getSettings(), clientContext);
+
+    this.backgroundResources =
+        new BackgroundResourceAggregation(clientContext.getBackgroundResources());
+  }
+
+  @InternalApi
+  public static List<ApiMethodDescriptor> getMethodDescriptors() {
+    List<ApiMethodDescriptor> methodDescriptors = new ArrayList<>();
+    methodDescriptors.add(getMethodDescriptor);
+    return methodDescriptors;
+  }
+
+  @Override
+  public UnaryCallable<GetRegionOperationRequest, Operation> getCallable() {
+    return getCallable;
+  }
+
+  @Override
+  public final void close() {
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
+  }
+
+  @Override
+  public void shutdown() {
+    backgroundResources.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return backgroundResources.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return backgroundResources.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    backgroundResources.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return backgroundResources.awaitTermination(duration, unit);
+  }
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/RegionOperationsStub.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/RegionOperationsStub.java
new file mode 100644
index 0000000000..c3019038cb
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/RegionOperationsStub.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.cloud.compute.v1.GetRegionOperationRequest;
+import com.google.cloud.compute.v1.Operation;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Base stub class for the RegionOperations service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@Generated("by gapic-generator-java")
+public abstract class RegionOperationsStub implements BackgroundResource {
+
+  public UnaryCallable<GetRegionOperationRequest, Operation> getCallable() {
+    throw new UnsupportedOperationException("Not implemented: getCallable()");
+  }
+
+  @Override
+  public abstract void close();
+}
diff --git a/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/RegionOperationsStubSettings.java b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/RegionOperationsStubSettings.java
new file mode 100644
index 0000000000..ebcf98e4f7
--- /dev/null
+++ b/test/integration/goldens/compute/com/google/cloud/compute/v1/stub/RegionOperationsStubSettings.java
@@ -0,0 +1,277 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.compute.v1.stub;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GaxProperties;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.httpjson.GaxHttpJsonProperties;
+import com.google.api.gax.httpjson.HttpJsonTransportChannel;
+import com.google.api.gax.httpjson.InstantiatingHttpJsonChannelProvider;
+import com.google.api.gax.retrying.RetrySettings;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.cloud.compute.v1.GetRegionOperationRequest;
+import com.google.cloud.compute.v1.Operation;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+import org.threeten.bp.Duration;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link RegionOperationsStub}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (compute.googleapis.com) and default port (443) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of get to 30 seconds:
+ *
+ * <pre>{@code
+ * RegionOperationsStubSettings.Builder regionOperationsSettingsBuilder =
+ *     RegionOperationsStubSettings.newBuilder();
+ * regionOperationsSettingsBuilder
+ *     .getSettings()
+ *     .setRetrySettings(
+ *         regionOperationsSettingsBuilder
+ *             .getSettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * RegionOperationsStubSettings regionOperationsSettings = regionOperationsSettingsBuilder.build();
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+public class RegionOperationsStubSettings extends StubSettings<RegionOperationsStubSettings> {
+  /** The default scopes of the service. */
+  private static final ImmutableList<String> DEFAULT_SERVICE_SCOPES =
+      ImmutableList.<String>builder()
+          .add("https://www.googleapis.com/auth/compute.readonly")
+          .add("https://www.googleapis.com/auth/compute")
+          .add("https://www.googleapis.com/auth/cloud-platform")
+          .build();
+
+  private final UnaryCallSettings<GetRegionOperationRequest, Operation> getSettings;
+
+  /** Returns the object with the settings used for calls to get. */
+  public UnaryCallSettings<GetRegionOperationRequest, Operation> getSettings() {
+    return getSettings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public RegionOperationsStub createStub() throws IOException {
+    if (getTransportChannelProvider()
+        .getTransportName()
+        .equals(HttpJsonTransportChannel.getHttpJsonTransportName())) {
+      return HttpJsonRegionOperationsStub.create(this);
+    }
+    throw new UnsupportedOperationException(
+        String.format(
+            "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return InstantiatingExecutorProvider.newBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return "compute.googleapis.com:443";
+  }
+
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "compute.mtls.googleapis.com:443";
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return DEFAULT_SERVICE_SCOPES;
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingHttpJsonChannelProvider.Builder
+      defaultHttpJsonTransportProviderBuilder() {
+    return InstantiatingHttpJsonChannelProvider.newBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return defaultHttpJsonTransportProviderBuilder().build();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return ApiClientHeaderProvider.newBuilder()
+        .setGeneratedLibToken(
+            "gapic", GaxProperties.getLibraryVersion(RegionOperationsStubSettings.class))
+        .setTransportToken(
+            GaxHttpJsonProperties.getHttpJsonTokenName(),
+            GaxHttpJsonProperties.getHttpJsonVersion());
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected RegionOperationsStubSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+
+    getSettings = settingsBuilder.getSettings().build();
+  }
+
+  /** Builder for RegionOperationsStubSettings. */
+  public static class Builder extends StubSettings.Builder<RegionOperationsStubSettings, Builder> {
+    private final ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders;
+    private final UnaryCallSettings.Builder<GetRegionOperationRequest, Operation> getSettings;
+    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
+        RETRYABLE_CODE_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
+          ImmutableMap.builder();
+      definitions.put(
+          "retry_policy_0_codes",
+          ImmutableSet.copyOf(
+              Lists.<StatusCode.Code>newArrayList(
+                  StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
+      RETRYABLE_CODE_DEFINITIONS = definitions.build();
+    }
+
+    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
+      RetrySettings settings = null;
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRetryDelay(Duration.ofMillis(100L))
+              .setRetryDelayMultiplier(1.3)
+              .setMaxRetryDelay(Duration.ofMillis(60000L))
+              .setInitialRpcTimeout(Duration.ofMillis(600000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(600000L))
+              .setTotalTimeout(Duration.ofMillis(600000L))
+              .build();
+      definitions.put("retry_policy_0_params", settings);
+      RETRY_PARAM_DEFINITIONS = definitions.build();
+    }
+
+    protected Builder() {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(clientContext);
+
+      getSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+
+      unaryMethodSettingsBuilders = ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(getSettings);
+      initDefaults(this);
+    }
+
+    protected Builder(RegionOperationsStubSettings settings) {
+      super(settings);
+
+      getSettings = settings.getSettings.toBuilder();
+
+      unaryMethodSettingsBuilders = ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(getSettings);
+    }
+
+    private static Builder createDefault() {
+      Builder builder = new Builder(((ClientContext) null));
+
+      builder.setTransportChannelProvider(defaultTransportChannelProvider());
+      builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
+      builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
+      builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
+
+      return initDefaults(builder);
+    }
+
+    private static Builder initDefaults(Builder builder) {
+      builder
+          .getSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
+
+      return builder;
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
+      return this;
+    }
+
+    public ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders() {
+      return unaryMethodSettingsBuilders;
+    }
+
+    /** Returns the builder for the settings used for calls to get. */
+    public UnaryCallSettings.Builder<GetRegionOperationRequest, Operation> getSettings() {
+      return getSettings;
+    }
+
+    @Override
+    public RegionOperationsStubSettings build() throws IOException {
+      return new RegionOperationsStubSettings(this);
+    }
+  }
+}
diff --git a/test/integration/goldens/credentials/BUILD.bazel b/test/integration/goldens/credentials/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/credentials/BUILD.bazel
+++ b/test/integration/goldens/credentials/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IAMCredentialsClientTest.java b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IAMCredentialsClientTest.java
index ad8fb75d32..e386fdec3c 100644
--- a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IAMCredentialsClientTest.java
+++ b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IAMCredentialsClientTest.java
@@ -43,10 +43,10 @@
 
 @Generated("by gapic-generator-java")
 public class IAMCredentialsClientTest {
-  private static MockServiceHelper mockServiceHelper;
   private static MockIAMCredentials mockIAMCredentials;
-  private IamCredentialsClient client;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private IamCredentialsClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java
index 9018bc6ffd..7395ce677d 100644
--- a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java
+++ b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java
@@ -175,14 +175,13 @@ public IamCredentialsStubSettings.Builder getStubSettingsBuilder() {
       return ((IamCredentialsStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/ServiceAccountName.java b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/ServiceAccountName.java
index dfca251fb1..148cbe58cb 100644
--- a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/ServiceAccountName.java
+++ b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/ServiceAccountName.java
@@ -182,8 +182,8 @@ public Builder setServiceAccount(String serviceAccount) {
     }
 
     private Builder(ServiceAccountName serviceAccountName) {
-      project = serviceAccountName.project;
-      serviceAccount = serviceAccountName.serviceAccount;
+      this.project = serviceAccountName.project;
+      this.serviceAccount = serviceAccountName.serviceAccount;
     }
 
     public ServiceAccountName build() {
diff --git a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/GrpcIamCredentialsStub.java b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/GrpcIamCredentialsStub.java
index 48731cd53d..8d57d52a19 100644
--- a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/GrpcIamCredentialsStub.java
+++ b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/GrpcIamCredentialsStub.java
@@ -21,7 +21,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.cloud.iam.credentials.v1.GenerateAccessTokenRequest;
 import com.google.cloud.iam.credentials.v1.GenerateAccessTokenResponse;
@@ -143,13 +142,10 @@ protected GrpcIamCredentialsStub(
             GrpcCallSettings.<GenerateAccessTokenRequest, GenerateAccessTokenResponse>newBuilder()
                 .setMethodDescriptor(generateAccessTokenMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<GenerateAccessTokenRequest>() {
-                      @Override
-                      public Map<String, String> extract(GenerateAccessTokenRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GenerateIdTokenRequest, GenerateIdTokenResponse>
@@ -157,39 +153,30 @@ public Map<String, String> extract(GenerateAccessTokenRequest request) {
             GrpcCallSettings.<GenerateIdTokenRequest, GenerateIdTokenResponse>newBuilder()
                 .setMethodDescriptor(generateIdTokenMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<GenerateIdTokenRequest>() {
-                      @Override
-                      public Map<String, String> extract(GenerateIdTokenRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<SignBlobRequest, SignBlobResponse> signBlobTransportSettings =
         GrpcCallSettings.<SignBlobRequest, SignBlobResponse>newBuilder()
             .setMethodDescriptor(signBlobMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SignBlobRequest>() {
-                  @Override
-                  public Map<String, String> extract(SignBlobRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<SignJwtRequest, SignJwtResponse> signJwtTransportSettings =
         GrpcCallSettings.<SignJwtRequest, SignJwtResponse>newBuilder()
             .setMethodDescriptor(signJwtMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SignJwtRequest>() {
-                  @Override
-                  public Map<String, String> extract(SignJwtRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
 
@@ -239,7 +226,13 @@ public UnaryCallable<SignJwtRequest, SignJwtResponse> signJwtCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java
index 0cec2d9668..26792da200 100644
--- a/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java
+++ b/test/integration/goldens/credentials/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java
@@ -138,6 +138,11 @@ public static String getDefaultEndpoint() {
     return "iamcredentials.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "iamcredentials.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -145,7 +150,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -277,6 +284,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -305,14 +314,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/iam/BUILD.bazel b/test/integration/goldens/iam/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/iam/BUILD.bazel
+++ b/test/integration/goldens/iam/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/iam/com/google/iam/v1/IAMPolicyClientTest.java b/test/integration/goldens/iam/com/google/iam/v1/IAMPolicyClientTest.java
index a055a7a204..fd1836ff9f 100644
--- a/test/integration/goldens/iam/com/google/iam/v1/IAMPolicyClientTest.java
+++ b/test/integration/goldens/iam/com/google/iam/v1/IAMPolicyClientTest.java
@@ -41,10 +41,10 @@
 
 @Generated("by gapic-generator-java")
 public class IAMPolicyClientTest {
-  private static MockServiceHelper mockServiceHelper;
-  private IAMPolicyClient client;
   private static MockIAMPolicy mockIAMPolicy;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private IAMPolicyClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/iam/com/google/iam/v1/IAMPolicySettings.java b/test/integration/goldens/iam/com/google/iam/v1/IAMPolicySettings.java
index a1c55c5782..26eb385562 100644
--- a/test/integration/goldens/iam/com/google/iam/v1/IAMPolicySettings.java
+++ b/test/integration/goldens/iam/com/google/iam/v1/IAMPolicySettings.java
@@ -166,14 +166,13 @@ public IAMPolicyStubSettings.Builder getStubSettingsBuilder() {
       return ((IAMPolicyStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/iam/com/google/iam/v1/package-info.java b/test/integration/goldens/iam/com/google/iam/v1/package-info.java
index 136353c3e3..8f87748c4b 100644
--- a/test/integration/goldens/iam/com/google/iam/v1/package-info.java
+++ b/test/integration/goldens/iam/com/google/iam/v1/package-info.java
@@ -48,7 +48,7 @@
  * try (IAMPolicyClient iAMPolicyClient = IAMPolicyClient.create()) {
  *   SetIamPolicyRequest request =
  *       SetIamPolicyRequest.newBuilder()
- *           .setResource("SetIamPolicyRequest1223629066".toString())
+ *           .setResource("resource-341064690")
  *           .setPolicy(Policy.newBuilder().build())
  *           .build();
  *   Policy response = iAMPolicyClient.setIamPolicy(request);
diff --git a/test/integration/goldens/iam/com/google/iam/v1/stub/GrpcIAMPolicyStub.java b/test/integration/goldens/iam/com/google/iam/v1/stub/GrpcIAMPolicyStub.java
index f40c2bfffe..1e19326973 100644
--- a/test/integration/goldens/iam/com/google/iam/v1/stub/GrpcIAMPolicyStub.java
+++ b/test/integration/goldens/iam/com/google/iam/v1/stub/GrpcIAMPolicyStub.java
@@ -21,7 +21,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.iam.v1.GetIamPolicyRequest;
@@ -122,26 +121,20 @@ protected GrpcIAMPolicyStub(
         GrpcCallSettings.<SetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(setIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(SetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetIamPolicyRequest, Policy> getIamPolicyTransportSettings =
         GrpcCallSettings.<GetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(getIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<TestIamPermissionsRequest, TestIamPermissionsResponse>
@@ -149,13 +142,10 @@ public Map<String, String> extract(GetIamPolicyRequest request) {
             GrpcCallSettings.<TestIamPermissionsRequest, TestIamPermissionsResponse>newBuilder()
                 .setMethodDescriptor(testIamPermissionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<TestIamPermissionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(TestIamPermissionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("resource", String.valueOf(request.getResource()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("resource", String.valueOf(request.getResource()));
+                      return params.build();
                     })
                 .build();
 
@@ -197,7 +187,13 @@ public UnaryCallable<GetIamPolicyRequest, Policy> getIamPolicyCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/iam/com/google/iam/v1/stub/IAMPolicyStubSettings.java b/test/integration/goldens/iam/com/google/iam/v1/stub/IAMPolicyStubSettings.java
index 5959e94a06..03c10fcb73 100644
--- a/test/integration/goldens/iam/com/google/iam/v1/stub/IAMPolicyStubSettings.java
+++ b/test/integration/goldens/iam/com/google/iam/v1/stub/IAMPolicyStubSettings.java
@@ -125,6 +125,11 @@ public static String getDefaultEndpoint() {
     return "iam-meta-api.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "iam-meta-api.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -132,7 +137,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -250,6 +257,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -273,14 +282,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/kms/BUILD.bazel b/test/integration/goldens/kms/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/kms/BUILD.bazel
+++ b/test/integration/goldens/kms/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyName.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyName.java
index ebad53ab26..3e782de33a 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyName.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyName.java
@@ -248,10 +248,10 @@ public Builder setCryptoKey(String cryptoKey) {
     }
 
     private Builder(CryptoKeyName cryptoKeyName) {
-      project = cryptoKeyName.project;
-      location = cryptoKeyName.location;
-      keyRing = cryptoKeyName.keyRing;
-      cryptoKey = cryptoKeyName.cryptoKey;
+      this.project = cryptoKeyName.project;
+      this.location = cryptoKeyName.location;
+      this.keyRing = cryptoKeyName.keyRing;
+      this.cryptoKey = cryptoKeyName.cryptoKey;
     }
 
     public CryptoKeyName build() {
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyVersionName.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyVersionName.java
index c9317320c2..f60ef735fc 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyVersionName.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/CryptoKeyVersionName.java
@@ -284,11 +284,11 @@ public Builder setCryptoKeyVersion(String cryptoKeyVersion) {
     }
 
     private Builder(CryptoKeyVersionName cryptoKeyVersionName) {
-      project = cryptoKeyVersionName.project;
-      location = cryptoKeyVersionName.location;
-      keyRing = cryptoKeyVersionName.keyRing;
-      cryptoKey = cryptoKeyVersionName.cryptoKey;
-      cryptoKeyVersion = cryptoKeyVersionName.cryptoKeyVersion;
+      this.project = cryptoKeyVersionName.project;
+      this.location = cryptoKeyVersionName.location;
+      this.keyRing = cryptoKeyVersionName.keyRing;
+      this.cryptoKey = cryptoKeyVersionName.cryptoKey;
+      this.cryptoKeyVersion = cryptoKeyVersionName.cryptoKeyVersion;
     }
 
     public CryptoKeyVersionName build() {
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/ImportJobName.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/ImportJobName.java
index 23b29da21a..8b966623be 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/ImportJobName.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/ImportJobName.java
@@ -248,10 +248,10 @@ public Builder setImportJob(String importJob) {
     }
 
     private Builder(ImportJobName importJobName) {
-      project = importJobName.project;
-      location = importJobName.location;
-      keyRing = importJobName.keyRing;
-      importJob = importJobName.importJob;
+      this.project = importJobName.project;
+      this.location = importJobName.location;
+      this.keyRing = importJobName.keyRing;
+      this.importJob = importJobName.importJob;
     }
 
     public ImportJobName build() {
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClient.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClient.java
index cc3e563cff..e4d0dcc548 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClient.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.kms.v1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -2148,7 +2147,7 @@ public final CryptoKeyVersion updateCryptoKeyVersion(UpdateCryptoKeyVersionReque
    * <pre>{@code
    * try (KeyManagementServiceClient keyManagementServiceClient =
    *     KeyManagementServiceClient.create()) {
-   *   ResourceName name = KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]");
+   *   ResourceName name = CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]");
    *   ByteString plaintext = ByteString.EMPTY;
    *   EncryptResponse response = keyManagementServiceClient.encrypt(name, plaintext);
    * }
@@ -2188,7 +2187,8 @@ public final EncryptResponse encrypt(ResourceName name, ByteString plaintext) {
    * <pre>{@code
    * try (KeyManagementServiceClient keyManagementServiceClient =
    *     KeyManagementServiceClient.create()) {
-   *   String name = KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString();
+   *   String name =
+   *       CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]").toString();
    *   ByteString plaintext = ByteString.EMPTY;
    *   EncryptResponse response = keyManagementServiceClient.encrypt(name, plaintext);
    * }
@@ -2227,7 +2227,9 @@ public final EncryptResponse encrypt(String name, ByteString plaintext) {
    *     KeyManagementServiceClient.create()) {
    *   EncryptRequest request =
    *       EncryptRequest.newBuilder()
-   *           .setName(KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString())
+   *           .setName(
+   *               CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]")
+   *                   .toString())
    *           .setPlaintext(ByteString.EMPTY)
    *           .setAdditionalAuthenticatedData(ByteString.EMPTY)
    *           .setPlaintextCrc32C(Int64Value.newBuilder().build())
@@ -2258,7 +2260,9 @@ public final EncryptResponse encrypt(EncryptRequest request) {
    *     KeyManagementServiceClient.create()) {
    *   EncryptRequest request =
    *       EncryptRequest.newBuilder()
-   *           .setName(KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString())
+   *           .setName(
+   *               CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]")
+   *                   .toString())
    *           .setPlaintext(ByteString.EMPTY)
    *           .setAdditionalAuthenticatedData(ByteString.EMPTY)
    *           .setPlaintextCrc32C(Int64Value.newBuilder().build())
@@ -3154,7 +3158,9 @@ public final CryptoKeyVersion restoreCryptoKeyVersion(RestoreCryptoKeyVersionReq
    *     KeyManagementServiceClient.create()) {
    *   GetIamPolicyRequest request =
    *       GetIamPolicyRequest.newBuilder()
-   *           .setResource(KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString())
+   *           .setResource(
+   *               CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]")
+   *                   .toString())
    *           .setOptions(GetPolicyOptions.newBuilder().build())
    *           .build();
    *   Policy response = keyManagementServiceClient.getIamPolicy(request);
@@ -3180,7 +3186,9 @@ public final Policy getIamPolicy(GetIamPolicyRequest request) {
    *     KeyManagementServiceClient.create()) {
    *   GetIamPolicyRequest request =
    *       GetIamPolicyRequest.newBuilder()
-   *           .setResource(KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString())
+   *           .setResource(
+   *               CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]")
+   *                   .toString())
    *           .setOptions(GetPolicyOptions.newBuilder().build())
    *           .build();
    *   ApiFuture<Policy> future =
@@ -3343,7 +3351,9 @@ public final UnaryCallable<GetLocationRequest, Location> getLocationCallable() {
    *     KeyManagementServiceClient.create()) {
    *   TestIamPermissionsRequest request =
    *       TestIamPermissionsRequest.newBuilder()
-   *           .setResource(KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString())
+   *           .setResource(
+   *               CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]")
+   *                   .toString())
    *           .addAllPermissions(new ArrayList<String>())
    *           .build();
    *   TestIamPermissionsResponse response = keyManagementServiceClient.testIamPermissions(request);
@@ -3369,7 +3379,9 @@ public final TestIamPermissionsResponse testIamPermissions(TestIamPermissionsReq
    *     KeyManagementServiceClient.create()) {
    *   TestIamPermissionsRequest request =
    *       TestIamPermissionsRequest.newBuilder()
-   *           .setResource(KeyRingName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]").toString())
+   *           .setResource(
+   *               CryptoKeyName.of("[PROJECT]", "[LOCATION]", "[KEY_RING]", "[CRYPTO_KEY]")
+   *                   .toString())
    *           .addAllPermissions(new ArrayList<String>())
    *           .build();
    *   ApiFuture<TestIamPermissionsResponse> future =
@@ -3429,12 +3441,7 @@ public static ApiFuture<ListKeyRingsPagedResponse> createAsync(
           ListKeyRingsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListKeyRingsPage, ListKeyRingsPagedResponse>() {
-            @Override
-            public ListKeyRingsPagedResponse apply(ListKeyRingsPage input) {
-              return new ListKeyRingsPagedResponse(input);
-            }
-          },
+          input -> new ListKeyRingsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -3509,12 +3516,7 @@ public static ApiFuture<ListCryptoKeysPagedResponse> createAsync(
           ListCryptoKeysPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListCryptoKeysPage, ListCryptoKeysPagedResponse>() {
-            @Override
-            public ListCryptoKeysPagedResponse apply(ListCryptoKeysPage input) {
-              return new ListCryptoKeysPagedResponse(input);
-            }
-          },
+          input -> new ListCryptoKeysPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -3591,12 +3593,7 @@ public static ApiFuture<ListCryptoKeyVersionsPagedResponse> createAsync(
           ListCryptoKeyVersionsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListCryptoKeyVersionsPage, ListCryptoKeyVersionsPagedResponse>() {
-            @Override
-            public ListCryptoKeyVersionsPagedResponse apply(ListCryptoKeyVersionsPage input) {
-              return new ListCryptoKeyVersionsPagedResponse(input);
-            }
-          },
+          input -> new ListCryptoKeyVersionsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -3679,12 +3676,7 @@ public static ApiFuture<ListImportJobsPagedResponse> createAsync(
           ListImportJobsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListImportJobsPage, ListImportJobsPagedResponse>() {
-            @Override
-            public ListImportJobsPagedResponse apply(ListImportJobsPage input) {
-              return new ListImportJobsPagedResponse(input);
-            }
-          },
+          input -> new ListImportJobsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -3760,12 +3752,7 @@ public static ApiFuture<ListLocationsPagedResponse> createAsync(
           ListLocationsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListLocationsPage, ListLocationsPagedResponse>() {
-            @Override
-            public ListLocationsPagedResponse apply(ListLocationsPage input) {
-              return new ListLocationsPagedResponse(input);
-            }
-          },
+          input -> new ListLocationsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java
index b1952fc8e3..29a0c79b67 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceClientTest.java
@@ -66,22 +66,22 @@
 
 @Generated("by gapic-generator-java")
 public class KeyManagementServiceClientTest {
-  private static MockKeyManagementService mockKeyManagementService;
-  private static MockServiceHelper mockServiceHelper;
-  private KeyManagementServiceClient client;
   private static MockIAMPolicy mockIAMPolicy;
+  private static MockKeyManagementService mockKeyManagementService;
   private static MockLocations mockLocations;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private KeyManagementServiceClient client;
 
   @BeforeClass
   public static void startStaticServer() {
     mockKeyManagementService = new MockKeyManagementService();
-    mockIAMPolicy = new MockIAMPolicy();
     mockLocations = new MockLocations();
+    mockIAMPolicy = new MockIAMPolicy();
     mockServiceHelper =
         new MockServiceHelper(
             UUID.randomUUID().toString(),
-            Arrays.<MockGrpcService>asList(mockKeyManagementService, mockIAMPolicy, mockLocations));
+            Arrays.<MockGrpcService>asList(mockKeyManagementService, mockLocations, mockIAMPolicy));
     mockServiceHelper.start();
   }
 
@@ -752,14 +752,7 @@ public void getPublicKeyTest() throws Exception {
         PublicKey.newBuilder()
             .setPem("pem110872")
             .setPemCrc32C(Int64Value.newBuilder().build())
-            .setName(
-                PublicKeyName.of(
-                        "[PROJECT]",
-                        "[LOCATION]",
-                        "[KEY_RING]",
-                        "[CRYPTO_KEY]",
-                        "[CRYPTO_KEY_VERSION]")
-                    .toString())
+            .setName("name3373707")
             .build();
     mockKeyManagementService.addResponse(expectedResponse);
 
@@ -803,14 +796,7 @@ public void getPublicKeyTest2() throws Exception {
         PublicKey.newBuilder()
             .setPem("pem110872")
             .setPemCrc32C(Int64Value.newBuilder().build())
-            .setName(
-                PublicKeyName.of(
-                        "[PROJECT]",
-                        "[LOCATION]",
-                        "[KEY_RING]",
-                        "[CRYPTO_KEY]",
-                        "[CRYPTO_KEY_VERSION]")
-                    .toString())
+            .setName("name3373707")
             .build();
     mockKeyManagementService.addResponse(expectedResponse);
 
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceSettings.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceSettings.java
index d749c91145..fb53484f12 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceSettings.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyManagementServiceSettings.java
@@ -324,14 +324,13 @@ public KeyManagementServiceStubSettings.Builder getStubSettingsBuilder() {
       return ((KeyManagementServiceStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyRingName.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyRingName.java
index 1deea50c8e..7938c9a34a 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyRingName.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/KeyRingName.java
@@ -211,9 +211,9 @@ public Builder setKeyRing(String keyRing) {
     }
 
     private Builder(KeyRingName keyRingName) {
-      project = keyRingName.project;
-      location = keyRingName.location;
-      keyRing = keyRingName.keyRing;
+      this.project = keyRingName.project;
+      this.location = keyRingName.location;
+      this.keyRing = keyRingName.keyRing;
     }
 
     public KeyRingName build() {
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/LocationName.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/LocationName.java
index bd6776a8cc..143d06cd6e 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/LocationName.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/LocationName.java
@@ -181,8 +181,8 @@ public Builder setLocation(String location) {
     }
 
     private Builder(LocationName locationName) {
-      project = locationName.project;
-      location = locationName.location;
+      this.project = locationName.project;
+      this.location = locationName.location;
     }
 
     public LocationName build() {
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/PublicKeyName.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/PublicKeyName.java
deleted file mode 100644
index 048fc3f413..0000000000
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/PublicKeyName.java
+++ /dev/null
@@ -1,298 +0,0 @@
-/*
- * Copyright 2021 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.google.cloud.kms.v1;
-
-import com.google.api.pathtemplate.PathTemplate;
-import com.google.api.resourcenames.ResourceName;
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableMap;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import javax.annotation.Generated;
-
-// AUTO-GENERATED DOCUMENTATION AND CLASS.
-@Generated("by gapic-generator-java")
-public class PublicKeyName implements ResourceName {
-  private static final PathTemplate PROJECT_LOCATION_KEY_RING_CRYPTO_KEY_CRYPTO_KEY_VERSION =
-      PathTemplate.createWithoutUrlEncoding(
-          "projects/{project}/locations/{location}/keyRings/{key_ring}/cryptoKeys/{crypto_key}/cryptoKeyVersions/{crypto_key_version}/publicKey");
-  private volatile Map<String, String> fieldValuesMap;
-  private final String project;
-  private final String location;
-  private final String keyRing;
-  private final String cryptoKey;
-  private final String cryptoKeyVersion;
-
-  @Deprecated
-  protected PublicKeyName() {
-    project = null;
-    location = null;
-    keyRing = null;
-    cryptoKey = null;
-    cryptoKeyVersion = null;
-  }
-
-  private PublicKeyName(Builder builder) {
-    project = Preconditions.checkNotNull(builder.getProject());
-    location = Preconditions.checkNotNull(builder.getLocation());
-    keyRing = Preconditions.checkNotNull(builder.getKeyRing());
-    cryptoKey = Preconditions.checkNotNull(builder.getCryptoKey());
-    cryptoKeyVersion = Preconditions.checkNotNull(builder.getCryptoKeyVersion());
-  }
-
-  public String getProject() {
-    return project;
-  }
-
-  public String getLocation() {
-    return location;
-  }
-
-  public String getKeyRing() {
-    return keyRing;
-  }
-
-  public String getCryptoKey() {
-    return cryptoKey;
-  }
-
-  public String getCryptoKeyVersion() {
-    return cryptoKeyVersion;
-  }
-
-  public static Builder newBuilder() {
-    return new Builder();
-  }
-
-  public Builder toBuilder() {
-    return new Builder(this);
-  }
-
-  public static PublicKeyName of(
-      String project, String location, String keyRing, String cryptoKey, String cryptoKeyVersion) {
-    return newBuilder()
-        .setProject(project)
-        .setLocation(location)
-        .setKeyRing(keyRing)
-        .setCryptoKey(cryptoKey)
-        .setCryptoKeyVersion(cryptoKeyVersion)
-        .build();
-  }
-
-  public static String format(
-      String project, String location, String keyRing, String cryptoKey, String cryptoKeyVersion) {
-    return newBuilder()
-        .setProject(project)
-        .setLocation(location)
-        .setKeyRing(keyRing)
-        .setCryptoKey(cryptoKey)
-        .setCryptoKeyVersion(cryptoKeyVersion)
-        .build()
-        .toString();
-  }
-
-  public static PublicKeyName parse(String formattedString) {
-    if (formattedString.isEmpty()) {
-      return null;
-    }
-    Map<String, String> matchMap =
-        PROJECT_LOCATION_KEY_RING_CRYPTO_KEY_CRYPTO_KEY_VERSION.validatedMatch(
-            formattedString, "PublicKeyName.parse: formattedString not in valid format");
-    return of(
-        matchMap.get("project"),
-        matchMap.get("location"),
-        matchMap.get("key_ring"),
-        matchMap.get("crypto_key"),
-        matchMap.get("crypto_key_version"));
-  }
-
-  public static List<PublicKeyName> parseList(List<String> formattedStrings) {
-    List<PublicKeyName> list = new ArrayList<>(formattedStrings.size());
-    for (String formattedString : formattedStrings) {
-      list.add(parse(formattedString));
-    }
-    return list;
-  }
-
-  public static List<String> toStringList(List<PublicKeyName> values) {
-    List<String> list = new ArrayList<>(values.size());
-    for (PublicKeyName value : values) {
-      if (value == null) {
-        list.add("");
-      } else {
-        list.add(value.toString());
-      }
-    }
-    return list;
-  }
-
-  public static boolean isParsableFrom(String formattedString) {
-    return PROJECT_LOCATION_KEY_RING_CRYPTO_KEY_CRYPTO_KEY_VERSION.matches(formattedString);
-  }
-
-  @Override
-  public Map<String, String> getFieldValuesMap() {
-    if (fieldValuesMap == null) {
-      synchronized (this) {
-        if (fieldValuesMap == null) {
-          ImmutableMap.Builder<String, String> fieldMapBuilder = ImmutableMap.builder();
-          if (project != null) {
-            fieldMapBuilder.put("project", project);
-          }
-          if (location != null) {
-            fieldMapBuilder.put("location", location);
-          }
-          if (keyRing != null) {
-            fieldMapBuilder.put("key_ring", keyRing);
-          }
-          if (cryptoKey != null) {
-            fieldMapBuilder.put("crypto_key", cryptoKey);
-          }
-          if (cryptoKeyVersion != null) {
-            fieldMapBuilder.put("crypto_key_version", cryptoKeyVersion);
-          }
-          fieldValuesMap = fieldMapBuilder.build();
-        }
-      }
-    }
-    return fieldValuesMap;
-  }
-
-  public String getFieldValue(String fieldName) {
-    return getFieldValuesMap().get(fieldName);
-  }
-
-  @Override
-  public String toString() {
-    return PROJECT_LOCATION_KEY_RING_CRYPTO_KEY_CRYPTO_KEY_VERSION.instantiate(
-        "project",
-        project,
-        "location",
-        location,
-        "key_ring",
-        keyRing,
-        "crypto_key",
-        cryptoKey,
-        "crypto_key_version",
-        cryptoKeyVersion);
-  }
-
-  @Override
-  public boolean equals(Object o) {
-    if (o == this) {
-      return true;
-    }
-    if (o != null || getClass() == o.getClass()) {
-      PublicKeyName that = ((PublicKeyName) o);
-      return Objects.equals(this.project, that.project)
-          && Objects.equals(this.location, that.location)
-          && Objects.equals(this.keyRing, that.keyRing)
-          && Objects.equals(this.cryptoKey, that.cryptoKey)
-          && Objects.equals(this.cryptoKeyVersion, that.cryptoKeyVersion);
-    }
-    return false;
-  }
-
-  @Override
-  public int hashCode() {
-    int h = 1;
-    h *= 1000003;
-    h ^= Objects.hashCode(project);
-    h *= 1000003;
-    h ^= Objects.hashCode(location);
-    h *= 1000003;
-    h ^= Objects.hashCode(keyRing);
-    h *= 1000003;
-    h ^= Objects.hashCode(cryptoKey);
-    h *= 1000003;
-    h ^= Objects.hashCode(cryptoKeyVersion);
-    return h;
-  }
-
-  /**
-   * Builder for
-   * projects/{project}/locations/{location}/keyRings/{key_ring}/cryptoKeys/{crypto_key}/cryptoKeyVersions/{crypto_key_version}/publicKey.
-   */
-  public static class Builder {
-    private String project;
-    private String location;
-    private String keyRing;
-    private String cryptoKey;
-    private String cryptoKeyVersion;
-
-    protected Builder() {}
-
-    public String getProject() {
-      return project;
-    }
-
-    public String getLocation() {
-      return location;
-    }
-
-    public String getKeyRing() {
-      return keyRing;
-    }
-
-    public String getCryptoKey() {
-      return cryptoKey;
-    }
-
-    public String getCryptoKeyVersion() {
-      return cryptoKeyVersion;
-    }
-
-    public Builder setProject(String project) {
-      this.project = project;
-      return this;
-    }
-
-    public Builder setLocation(String location) {
-      this.location = location;
-      return this;
-    }
-
-    public Builder setKeyRing(String keyRing) {
-      this.keyRing = keyRing;
-      return this;
-    }
-
-    public Builder setCryptoKey(String cryptoKey) {
-      this.cryptoKey = cryptoKey;
-      return this;
-    }
-
-    public Builder setCryptoKeyVersion(String cryptoKeyVersion) {
-      this.cryptoKeyVersion = cryptoKeyVersion;
-      return this;
-    }
-
-    private Builder(PublicKeyName publicKeyName) {
-      project = publicKeyName.project;
-      location = publicKeyName.location;
-      keyRing = publicKeyName.keyRing;
-      cryptoKey = publicKeyName.cryptoKey;
-      cryptoKeyVersion = publicKeyName.cryptoKeyVersion;
-    }
-
-    public PublicKeyName build() {
-      return new PublicKeyName(this);
-    }
-  }
-}
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/GrpcKeyManagementServiceStub.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/GrpcKeyManagementServiceStub.java
index 19065361ed..b1566ca46c 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/GrpcKeyManagementServiceStub.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/GrpcKeyManagementServiceStub.java
@@ -27,7 +27,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.cloud.kms.v1.AsymmetricDecryptRequest;
 import com.google.cloud.kms.v1.AsymmetricDecryptResponse;
@@ -451,13 +450,10 @@ protected GrpcKeyManagementServiceStub(
         GrpcCallSettings.<ListKeyRingsRequest, ListKeyRingsResponse>newBuilder()
             .setMethodDescriptor(listKeyRingsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListKeyRingsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListKeyRingsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListCryptoKeysRequest, ListCryptoKeysResponse>
@@ -465,13 +461,10 @@ public Map<String, String> extract(ListKeyRingsRequest request) {
             GrpcCallSettings.<ListCryptoKeysRequest, ListCryptoKeysResponse>newBuilder()
                 .setMethodDescriptor(listCryptoKeysMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListCryptoKeysRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListCryptoKeysRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ListCryptoKeyVersionsRequest, ListCryptoKeyVersionsResponse>
@@ -480,13 +473,10 @@ public Map<String, String> extract(ListCryptoKeysRequest request) {
                 .<ListCryptoKeyVersionsRequest, ListCryptoKeyVersionsResponse>newBuilder()
                 .setMethodDescriptor(listCryptoKeyVersionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListCryptoKeyVersionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListCryptoKeyVersionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ListImportJobsRequest, ListImportJobsResponse>
@@ -494,39 +484,30 @@ public Map<String, String> extract(ListCryptoKeyVersionsRequest request) {
             GrpcCallSettings.<ListImportJobsRequest, ListImportJobsResponse>newBuilder()
                 .setMethodDescriptor(listImportJobsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListImportJobsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListImportJobsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetKeyRingRequest, KeyRing> getKeyRingTransportSettings =
         GrpcCallSettings.<GetKeyRingRequest, KeyRing>newBuilder()
             .setMethodDescriptor(getKeyRingMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetKeyRingRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetKeyRingRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetCryptoKeyRequest, CryptoKey> getCryptoKeyTransportSettings =
         GrpcCallSettings.<GetCryptoKeyRequest, CryptoKey>newBuilder()
             .setMethodDescriptor(getCryptoKeyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetCryptoKeyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetCryptoKeyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetCryptoKeyVersionRequest, CryptoKeyVersion>
@@ -534,65 +515,50 @@ public Map<String, String> extract(GetCryptoKeyRequest request) {
             GrpcCallSettings.<GetCryptoKeyVersionRequest, CryptoKeyVersion>newBuilder()
                 .setMethodDescriptor(getCryptoKeyVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<GetCryptoKeyVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(GetCryptoKeyVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetPublicKeyRequest, PublicKey> getPublicKeyTransportSettings =
         GrpcCallSettings.<GetPublicKeyRequest, PublicKey>newBuilder()
             .setMethodDescriptor(getPublicKeyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetPublicKeyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetPublicKeyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetImportJobRequest, ImportJob> getImportJobTransportSettings =
         GrpcCallSettings.<GetImportJobRequest, ImportJob>newBuilder()
             .setMethodDescriptor(getImportJobMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetImportJobRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetImportJobRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateKeyRingRequest, KeyRing> createKeyRingTransportSettings =
         GrpcCallSettings.<CreateKeyRingRequest, KeyRing>newBuilder()
             .setMethodDescriptor(createKeyRingMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateKeyRingRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateKeyRingRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateCryptoKeyRequest, CryptoKey> createCryptoKeyTransportSettings =
         GrpcCallSettings.<CreateCryptoKeyRequest, CryptoKey>newBuilder()
             .setMethodDescriptor(createCryptoKeyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateCryptoKeyRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateCryptoKeyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateCryptoKeyVersionRequest, CryptoKeyVersion>
@@ -600,13 +566,10 @@ public Map<String, String> extract(CreateCryptoKeyRequest request) {
             GrpcCallSettings.<CreateCryptoKeyVersionRequest, CryptoKeyVersion>newBuilder()
                 .setMethodDescriptor(createCryptoKeyVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<CreateCryptoKeyVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(CreateCryptoKeyVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ImportCryptoKeyVersionRequest, CryptoKeyVersion>
@@ -614,39 +577,30 @@ public Map<String, String> extract(CreateCryptoKeyVersionRequest request) {
             GrpcCallSettings.<ImportCryptoKeyVersionRequest, CryptoKeyVersion>newBuilder()
                 .setMethodDescriptor(importCryptoKeyVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ImportCryptoKeyVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(ImportCryptoKeyVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<CreateImportJobRequest, ImportJob> createImportJobTransportSettings =
         GrpcCallSettings.<CreateImportJobRequest, ImportJob>newBuilder()
             .setMethodDescriptor(createImportJobMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateImportJobRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateImportJobRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateCryptoKeyRequest, CryptoKey> updateCryptoKeyTransportSettings =
         GrpcCallSettings.<UpdateCryptoKeyRequest, CryptoKey>newBuilder()
             .setMethodDescriptor(updateCryptoKeyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateCryptoKeyRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateCryptoKeyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("crypto_key.name", String.valueOf(request.getCryptoKey().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("crypto_key.name", String.valueOf(request.getCryptoKey().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateCryptoKeyVersionRequest, CryptoKeyVersion>
@@ -654,41 +608,32 @@ public Map<String, String> extract(UpdateCryptoKeyRequest request) {
             GrpcCallSettings.<UpdateCryptoKeyVersionRequest, CryptoKeyVersion>newBuilder()
                 .setMethodDescriptor(updateCryptoKeyVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<UpdateCryptoKeyVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(UpdateCryptoKeyVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put(
-                            "crypto_key_version.name",
-                            String.valueOf(request.getCryptoKeyVersion().getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put(
+                          "crypto_key_version.name",
+                          String.valueOf(request.getCryptoKeyVersion().getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<EncryptRequest, EncryptResponse> encryptTransportSettings =
         GrpcCallSettings.<EncryptRequest, EncryptResponse>newBuilder()
             .setMethodDescriptor(encryptMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<EncryptRequest>() {
-                  @Override
-                  public Map<String, String> extract(EncryptRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DecryptRequest, DecryptResponse> decryptTransportSettings =
         GrpcCallSettings.<DecryptRequest, DecryptResponse>newBuilder()
             .setMethodDescriptor(decryptMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DecryptRequest>() {
-                  @Override
-                  public Map<String, String> extract(DecryptRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<AsymmetricSignRequest, AsymmetricSignResponse>
@@ -696,13 +641,10 @@ public Map<String, String> extract(DecryptRequest request) {
             GrpcCallSettings.<AsymmetricSignRequest, AsymmetricSignResponse>newBuilder()
                 .setMethodDescriptor(asymmetricSignMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<AsymmetricSignRequest>() {
-                      @Override
-                      public Map<String, String> extract(AsymmetricSignRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<AsymmetricDecryptRequest, AsymmetricDecryptResponse>
@@ -710,13 +652,10 @@ public Map<String, String> extract(AsymmetricSignRequest request) {
             GrpcCallSettings.<AsymmetricDecryptRequest, AsymmetricDecryptResponse>newBuilder()
                 .setMethodDescriptor(asymmetricDecryptMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<AsymmetricDecryptRequest>() {
-                      @Override
-                      public Map<String, String> extract(AsymmetricDecryptRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<UpdateCryptoKeyPrimaryVersionRequest, CryptoKey>
@@ -724,14 +663,10 @@ public Map<String, String> extract(AsymmetricDecryptRequest request) {
             GrpcCallSettings.<UpdateCryptoKeyPrimaryVersionRequest, CryptoKey>newBuilder()
                 .setMethodDescriptor(updateCryptoKeyPrimaryVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<UpdateCryptoKeyPrimaryVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(
-                          UpdateCryptoKeyPrimaryVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<DestroyCryptoKeyVersionRequest, CryptoKeyVersion>
@@ -739,13 +674,10 @@ public Map<String, String> extract(
             GrpcCallSettings.<DestroyCryptoKeyVersionRequest, CryptoKeyVersion>newBuilder()
                 .setMethodDescriptor(destroyCryptoKeyVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<DestroyCryptoKeyVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(DestroyCryptoKeyVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<RestoreCryptoKeyVersionRequest, CryptoKeyVersion>
@@ -753,53 +685,41 @@ public Map<String, String> extract(DestroyCryptoKeyVersionRequest request) {
             GrpcCallSettings.<RestoreCryptoKeyVersionRequest, CryptoKeyVersion>newBuilder()
                 .setMethodDescriptor(restoreCryptoKeyVersionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<RestoreCryptoKeyVersionRequest>() {
-                      @Override
-                      public Map<String, String> extract(RestoreCryptoKeyVersionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("name", String.valueOf(request.getName()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("name", String.valueOf(request.getName()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetIamPolicyRequest, Policy> getIamPolicyTransportSettings =
         GrpcCallSettings.<GetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(getIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListLocationsRequest, ListLocationsResponse> listLocationsTransportSettings =
         GrpcCallSettings.<ListLocationsRequest, ListLocationsResponse>newBuilder()
             .setMethodDescriptor(listLocationsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListLocationsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListLocationsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("filter", String.valueOf(request.getFilter()));
-                    params.put("page_size", String.valueOf(request.getPageSize()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("filter", String.valueOf(request.getFilter()));
+                  params.put("page_size", String.valueOf(request.getPageSize()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetLocationRequest, Location> getLocationTransportSettings =
         GrpcCallSettings.<GetLocationRequest, Location>newBuilder()
             .setMethodDescriptor(getLocationMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetLocationRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetLocationRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<TestIamPermissionsRequest, TestIamPermissionsResponse>
@@ -807,13 +727,10 @@ public Map<String, String> extract(GetLocationRequest request) {
             GrpcCallSettings.<TestIamPermissionsRequest, TestIamPermissionsResponse>newBuilder()
                 .setMethodDescriptor(testIamPermissionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<TestIamPermissionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(TestIamPermissionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("resource", String.valueOf(request.getResource()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("resource", String.valueOf(request.getResource()));
+                      return params.build();
                     })
                 .build();
 
@@ -1119,7 +1036,13 @@ public UnaryCallable<GetLocationRequest, Location> getLocationCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java b/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java
index 5ebc43167f..e3faa10060 100644
--- a/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java
+++ b/test/integration/goldens/kms/com/google/cloud/kms/v1/stub/KeyManagementServiceStubSettings.java
@@ -645,6 +645,11 @@ public static String getDefaultEndpoint() {
     return "cloudkms.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "cloudkms.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -652,7 +657,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -962,6 +969,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -1105,14 +1114,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/kms/com/google/iam/v1/MockIAMPolicyImpl.java b/test/integration/goldens/kms/com/google/iam/v1/MockIAMPolicyImpl.java
index 6245f271c9..d1c753da0d 100644
--- a/test/integration/goldens/kms/com/google/iam/v1/MockIAMPolicyImpl.java
+++ b/test/integration/goldens/kms/com/google/iam/v1/MockIAMPolicyImpl.java
@@ -59,11 +59,13 @@ public void reset() {
   }
 
   @Override
-  public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> responseObserver) {
+  public void testIamPermissions(
+      TestIamPermissionsRequest request,
+      StreamObserver<TestIamPermissionsResponse> responseObserver) {
     Object response = responses.poll();
-    if (response instanceof Policy) {
+    if (response instanceof TestIamPermissionsResponse) {
       requests.add(request);
-      responseObserver.onNext(((Policy) response));
+      responseObserver.onNext(((TestIamPermissionsResponse) response));
       responseObserver.onCompleted();
     } else if (response instanceof Exception) {
       responseObserver.onError(((Exception) response));
@@ -71,21 +73,19 @@ public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> res
       responseObserver.onError(
           new IllegalArgumentException(
               String.format(
-                  "Unrecognized response type %s for method GetIamPolicy, expected %s or %s",
+                  "Unrecognized response type %s for method TestIamPermissions, expected %s or %s",
                   response == null ? "null" : response.getClass().getName(),
-                  Policy.class.getName(),
+                  TestIamPermissionsResponse.class.getName(),
                   Exception.class.getName())));
     }
   }
 
   @Override
-  public void testIamPermissions(
-      TestIamPermissionsRequest request,
-      StreamObserver<TestIamPermissionsResponse> responseObserver) {
+  public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> responseObserver) {
     Object response = responses.poll();
-    if (response instanceof TestIamPermissionsResponse) {
+    if (response instanceof Policy) {
       requests.add(request);
-      responseObserver.onNext(((TestIamPermissionsResponse) response));
+      responseObserver.onNext(((Policy) response));
       responseObserver.onCompleted();
     } else if (response instanceof Exception) {
       responseObserver.onError(((Exception) response));
@@ -93,9 +93,9 @@ public void testIamPermissions(
       responseObserver.onError(
           new IllegalArgumentException(
               String.format(
-                  "Unrecognized response type %s for method TestIamPermissions, expected %s or %s",
+                  "Unrecognized response type %s for method GetIamPolicy, expected %s or %s",
                   response == null ? "null" : response.getClass().getName(),
-                  TestIamPermissionsResponse.class.getName(),
+                  Policy.class.getName(),
                   Exception.class.getName())));
     }
   }
diff --git a/test/integration/goldens/library/BUILD.bazel b/test/integration/goldens/library/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/library/BUILD.bazel
+++ b/test/integration/goldens/library/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClient.java b/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClient.java
index a1dad2c9c7..3a758ad3f9 100644
--- a/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClient.java
+++ b/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.example.library.v1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -47,6 +46,7 @@
 import com.google.example.library.v1.ShelfName;
 import com.google.example.library.v1.UpdateBookRequest;
 import com.google.protobuf.Empty;
+import com.google.protobuf.FieldMask;
 import java.io.IOException;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -264,7 +264,7 @@ public final Shelf getShelf(ShelfName name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
+   *   String name = ShelfName.of("[SHELF_ID]").toString();
    *   Shelf response = libraryServiceClient.getShelf(name);
    * }
    * }</pre>
@@ -285,7 +285,8 @@ public final Shelf getShelf(String name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   GetShelfRequest request = GetShelfRequest.newBuilder().setName("name3373707").build();
+   *   GetShelfRequest request =
+   *       GetShelfRequest.newBuilder().setName(ShelfName.of("[SHELF_ID]").toString()).build();
    *   Shelf response = libraryServiceClient.getShelf(request);
    * }
    * }</pre>
@@ -305,7 +306,8 @@ public final Shelf getShelf(GetShelfRequest request) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   GetShelfRequest request = GetShelfRequest.newBuilder().setName("name3373707").build();
+   *   GetShelfRequest request =
+   *       GetShelfRequest.newBuilder().setName(ShelfName.of("[SHELF_ID]").toString()).build();
    *   ApiFuture<Shelf> future = libraryServiceClient.getShelfCallable().futureCall(request);
    *   // Do something.
    *   Shelf response = future.get();
@@ -433,7 +435,7 @@ public final void deleteShelf(ShelfName name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
+   *   String name = ShelfName.of("[SHELF_ID]").toString();
    *   libraryServiceClient.deleteShelf(name);
    * }
    * }</pre>
@@ -454,7 +456,8 @@ public final void deleteShelf(String name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   DeleteShelfRequest request = DeleteShelfRequest.newBuilder().setName("name3373707").build();
+   *   DeleteShelfRequest request =
+   *       DeleteShelfRequest.newBuilder().setName(ShelfName.of("[SHELF_ID]").toString()).build();
    *   libraryServiceClient.deleteShelf(request);
    * }
    * }</pre>
@@ -474,7 +477,8 @@ public final void deleteShelf(DeleteShelfRequest request) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   DeleteShelfRequest request = DeleteShelfRequest.newBuilder().setName("name3373707").build();
+   *   DeleteShelfRequest request =
+   *       DeleteShelfRequest.newBuilder().setName(ShelfName.of("[SHELF_ID]").toString()).build();
    *   ApiFuture<Empty> future = libraryServiceClient.deleteShelfCallable().futureCall(request);
    *   // Do something.
    *   future.get();
@@ -499,20 +503,20 @@ public final UnaryCallable<DeleteShelfRequest, Empty> deleteShelfCallable() {
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   ShelfName name = ShelfName.of("[SHELF_ID]");
-   *   ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
-   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelfName);
+   *   ShelfName otherShelf = ShelfName.of("[SHELF_ID]");
+   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelf);
    * }
    * }</pre>
    *
    * @param name The name of the shelf we're adding books to.
-   * @param otherShelfName The name of the shelf we're removing books from and deleting.
+   * @param otherShelf The name of the shelf we're removing books from and deleting.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Shelf mergeShelves(ShelfName name, ShelfName otherShelfName) {
+  public final Shelf mergeShelves(ShelfName name, ShelfName otherShelf) {
     MergeShelvesRequest request =
         MergeShelvesRequest.newBuilder()
             .setName(name == null ? null : name.toString())
-            .setOtherShelfName(otherShelfName == null ? null : otherShelfName.toString())
+            .setOtherShelf(otherShelf == null ? null : otherShelf.toString())
             .build();
     return mergeShelves(request);
   }
@@ -531,20 +535,20 @@ public final Shelf mergeShelves(ShelfName name, ShelfName otherShelfName) {
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   ShelfName name = ShelfName.of("[SHELF_ID]");
-   *   String otherShelfName = "otherShelfName-1942963547";
-   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelfName);
+   *   String otherShelf = ShelfName.of("[SHELF_ID]").toString();
+   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelf);
    * }
    * }</pre>
    *
    * @param name The name of the shelf we're adding books to.
-   * @param otherShelfName The name of the shelf we're removing books from and deleting.
+   * @param otherShelf The name of the shelf we're removing books from and deleting.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Shelf mergeShelves(ShelfName name, String otherShelfName) {
+  public final Shelf mergeShelves(ShelfName name, String otherShelf) {
     MergeShelvesRequest request =
         MergeShelvesRequest.newBuilder()
             .setName(name == null ? null : name.toString())
-            .setOtherShelfName(otherShelfName)
+            .setOtherShelf(otherShelf)
             .build();
     return mergeShelves(request);
   }
@@ -562,21 +566,21 @@ public final Shelf mergeShelves(ShelfName name, String otherShelfName) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
-   *   ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
-   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelfName);
+   *   String name = ShelfName.of("[SHELF_ID]").toString();
+   *   ShelfName otherShelf = ShelfName.of("[SHELF_ID]");
+   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelf);
    * }
    * }</pre>
    *
    * @param name The name of the shelf we're adding books to.
-   * @param otherShelfName The name of the shelf we're removing books from and deleting.
+   * @param otherShelf The name of the shelf we're removing books from and deleting.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Shelf mergeShelves(String name, ShelfName otherShelfName) {
+  public final Shelf mergeShelves(String name, ShelfName otherShelf) {
     MergeShelvesRequest request =
         MergeShelvesRequest.newBuilder()
             .setName(name)
-            .setOtherShelfName(otherShelfName == null ? null : otherShelfName.toString())
+            .setOtherShelf(otherShelf == null ? null : otherShelf.toString())
             .build();
     return mergeShelves(request);
   }
@@ -594,19 +598,19 @@ public final Shelf mergeShelves(String name, ShelfName otherShelfName) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
-   *   String otherShelfName = "otherShelfName-1942963547";
-   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelfName);
+   *   String name = ShelfName.of("[SHELF_ID]").toString();
+   *   String otherShelf = ShelfName.of("[SHELF_ID]").toString();
+   *   Shelf response = libraryServiceClient.mergeShelves(name, otherShelf);
    * }
    * }</pre>
    *
    * @param name The name of the shelf we're adding books to.
-   * @param otherShelfName The name of the shelf we're removing books from and deleting.
+   * @param otherShelf The name of the shelf we're removing books from and deleting.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Shelf mergeShelves(String name, String otherShelfName) {
+  public final Shelf mergeShelves(String name, String otherShelf) {
     MergeShelvesRequest request =
-        MergeShelvesRequest.newBuilder().setName(name).setOtherShelfName(otherShelfName).build();
+        MergeShelvesRequest.newBuilder().setName(name).setOtherShelf(otherShelf).build();
     return mergeShelves(request);
   }
 
@@ -625,8 +629,8 @@ public final Shelf mergeShelves(String name, String otherShelfName) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   MergeShelvesRequest request =
    *       MergeShelvesRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setOtherShelfName("otherShelfName-1942963547")
+   *           .setName(ShelfName.of("[SHELF_ID]").toString())
+   *           .setOtherShelf(ShelfName.of("[SHELF_ID]").toString())
    *           .build();
    *   Shelf response = libraryServiceClient.mergeShelves(request);
    * }
@@ -654,8 +658,8 @@ public final Shelf mergeShelves(MergeShelvesRequest request) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   MergeShelvesRequest request =
    *       MergeShelvesRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setOtherShelfName("otherShelfName-1942963547")
+   *           .setName(ShelfName.of("[SHELF_ID]").toString())
+   *           .setOtherShelf(ShelfName.of("[SHELF_ID]").toString())
    *           .build();
    *   ApiFuture<Shelf> future = libraryServiceClient.mergeShelvesCallable().futureCall(request);
    *   // Do something.
@@ -675,20 +679,20 @@ public final UnaryCallable<MergeShelvesRequest, Shelf> mergeShelvesCallable() {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   ShelfName name = ShelfName.of("[SHELF_ID]");
+   *   ShelfName parent = ShelfName.of("[SHELF_ID]");
    *   Book book = Book.newBuilder().build();
-   *   Book response = libraryServiceClient.createBook(name, book);
+   *   Book response = libraryServiceClient.createBook(parent, book);
    * }
    * }</pre>
    *
-   * @param name The name of the shelf in which the book is created.
+   * @param parent The name of the shelf in which the book is created.
    * @param book The book to create.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Book createBook(ShelfName name, Book book) {
+  public final Book createBook(ShelfName parent, Book book) {
     CreateBookRequest request =
         CreateBookRequest.newBuilder()
-            .setName(name == null ? null : name.toString())
+            .setParent(parent == null ? null : parent.toString())
             .setBook(book)
             .build();
     return createBook(request);
@@ -702,18 +706,19 @@ public final Book createBook(ShelfName name, Book book) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
+   *   String parent = ShelfName.of("[SHELF_ID]").toString();
    *   Book book = Book.newBuilder().build();
-   *   Book response = libraryServiceClient.createBook(name, book);
+   *   Book response = libraryServiceClient.createBook(parent, book);
    * }
    * }</pre>
    *
-   * @param name The name of the shelf in which the book is created.
+   * @param parent The name of the shelf in which the book is created.
    * @param book The book to create.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Book createBook(String name, Book book) {
-    CreateBookRequest request = CreateBookRequest.newBuilder().setName(name).setBook(book).build();
+  public final Book createBook(String parent, Book book) {
+    CreateBookRequest request =
+        CreateBookRequest.newBuilder().setParent(parent).setBook(book).build();
     return createBook(request);
   }
 
@@ -727,7 +732,7 @@ public final Book createBook(String name, Book book) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   CreateBookRequest request =
    *       CreateBookRequest.newBuilder()
-   *           .setName("name3373707")
+   *           .setParent(ShelfName.of("[SHELF_ID]").toString())
    *           .setBook(Book.newBuilder().build())
    *           .build();
    *   Book response = libraryServiceClient.createBook(request);
@@ -751,7 +756,7 @@ public final Book createBook(CreateBookRequest request) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   CreateBookRequest request =
    *       CreateBookRequest.newBuilder()
-   *           .setName("name3373707")
+   *           .setParent(ShelfName.of("[SHELF_ID]").toString())
    *           .setBook(Book.newBuilder().build())
    *           .build();
    *   ApiFuture<Book> future = libraryServiceClient.createBookCallable().futureCall(request);
@@ -772,7 +777,7 @@ public final UnaryCallable<CreateBookRequest, Book> createBookCallable() {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+   *   BookName name = BookName.of("[SHELF]", "[BOOK]");
    *   Book response = libraryServiceClient.getBook(name);
    * }
    * }</pre>
@@ -794,7 +799,7 @@ public final Book getBook(BookName name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
+   *   String name = BookName.of("[SHELF]", "[BOOK]").toString();
    *   Book response = libraryServiceClient.getBook(name);
    * }
    * }</pre>
@@ -815,7 +820,8 @@ public final Book getBook(String name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   GetBookRequest request = GetBookRequest.newBuilder().setName("name3373707").build();
+   *   GetBookRequest request =
+   *       GetBookRequest.newBuilder().setName(BookName.of("[SHELF]", "[BOOK]").toString()).build();
    *   Book response = libraryServiceClient.getBook(request);
    * }
    * }</pre>
@@ -835,7 +841,8 @@ public final Book getBook(GetBookRequest request) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   GetBookRequest request = GetBookRequest.newBuilder().setName("name3373707").build();
+   *   GetBookRequest request =
+   *       GetBookRequest.newBuilder().setName(BookName.of("[SHELF]", "[BOOK]").toString()).build();
    *   ApiFuture<Book> future = libraryServiceClient.getBookCallable().futureCall(request);
    *   // Do something.
    *   Book response = future.get();
@@ -856,19 +863,19 @@ public final UnaryCallable<GetBookRequest, Book> getBookCallable() {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   ShelfName name = ShelfName.of("[SHELF_ID]");
-   *   for (Book element : libraryServiceClient.listBooks(name).iterateAll()) {
+   *   ShelfName parent = ShelfName.of("[SHELF_ID]");
+   *   for (Book element : libraryServiceClient.listBooks(parent).iterateAll()) {
    *     // doThingsWith(element);
    *   }
    * }
    * }</pre>
    *
-   * @param name The name of the shelf whose books we'd like to list.
+   * @param parent The name of the shelf whose books we'd like to list.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final ListBooksPagedResponse listBooks(ShelfName name) {
+  public final ListBooksPagedResponse listBooks(ShelfName parent) {
     ListBooksRequest request =
-        ListBooksRequest.newBuilder().setName(name == null ? null : name.toString()).build();
+        ListBooksRequest.newBuilder().setParent(parent == null ? null : parent.toString()).build();
     return listBooks(request);
   }
 
@@ -882,18 +889,18 @@ public final ListBooksPagedResponse listBooks(ShelfName name) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
-   *   for (Book element : libraryServiceClient.listBooks(name).iterateAll()) {
+   *   String parent = ShelfName.of("[SHELF_ID]").toString();
+   *   for (Book element : libraryServiceClient.listBooks(parent).iterateAll()) {
    *     // doThingsWith(element);
    *   }
    * }
    * }</pre>
    *
-   * @param name The name of the shelf whose books we'd like to list.
+   * @param parent The name of the shelf whose books we'd like to list.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final ListBooksPagedResponse listBooks(String name) {
-    ListBooksRequest request = ListBooksRequest.newBuilder().setName(name).build();
+  public final ListBooksPagedResponse listBooks(String parent) {
+    ListBooksRequest request = ListBooksRequest.newBuilder().setParent(parent).build();
     return listBooks(request);
   }
 
@@ -909,7 +916,7 @@ public final ListBooksPagedResponse listBooks(String name) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   ListBooksRequest request =
    *       ListBooksRequest.newBuilder()
-   *           .setName("name3373707")
+   *           .setParent(ShelfName.of("[SHELF_ID]").toString())
    *           .setPageSize(883849137)
    *           .setPageToken("pageToken873572522")
    *           .build();
@@ -938,7 +945,7 @@ public final ListBooksPagedResponse listBooks(ListBooksRequest request) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   ListBooksRequest request =
    *       ListBooksRequest.newBuilder()
-   *           .setName("name3373707")
+   *           .setParent(ShelfName.of("[SHELF_ID]").toString())
    *           .setPageSize(883849137)
    *           .setPageToken("pageToken873572522")
    *           .build();
@@ -966,7 +973,7 @@ public final UnaryCallable<ListBooksRequest, ListBooksPagedResponse> listBooksPa
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   ListBooksRequest request =
    *       ListBooksRequest.newBuilder()
-   *           .setName("name3373707")
+   *           .setParent(ShelfName.of("[SHELF_ID]").toString())
    *           .setPageSize(883849137)
    *           .setPageToken("pageToken873572522")
    *           .build();
@@ -997,7 +1004,53 @@ public final UnaryCallable<ListBooksRequest, ListBooksResponse> listBooksCallabl
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   DeleteBookRequest request = DeleteBookRequest.newBuilder().setName("name3373707").build();
+   *   BookName name = BookName.of("[SHELF]", "[BOOK]");
+   *   libraryServiceClient.deleteBook(name);
+   * }
+   * }</pre>
+   *
+   * @param name The name of the book to delete.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final void deleteBook(BookName name) {
+    DeleteBookRequest request =
+        DeleteBookRequest.newBuilder().setName(name == null ? null : name.toString()).build();
+    deleteBook(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Deletes a book. Returns NOT_FOUND if the book does not exist.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
+   *   String name = BookName.of("[SHELF]", "[BOOK]").toString();
+   *   libraryServiceClient.deleteBook(name);
+   * }
+   * }</pre>
+   *
+   * @param name The name of the book to delete.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final void deleteBook(String name) {
+    DeleteBookRequest request = DeleteBookRequest.newBuilder().setName(name).build();
+    deleteBook(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Deletes a book. Returns NOT_FOUND if the book does not exist.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
+   *   DeleteBookRequest request =
+   *       DeleteBookRequest.newBuilder()
+   *           .setName(BookName.of("[SHELF]", "[BOOK]").toString())
+   *           .build();
    *   libraryServiceClient.deleteBook(request);
    * }
    * }</pre>
@@ -1017,7 +1070,10 @@ public final void deleteBook(DeleteBookRequest request) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   DeleteBookRequest request = DeleteBookRequest.newBuilder().setName("name3373707").build();
+   *   DeleteBookRequest request =
+   *       DeleteBookRequest.newBuilder()
+   *           .setName(BookName.of("[SHELF]", "[BOOK]").toString())
+   *           .build();
    *   ApiFuture<Empty> future = libraryServiceClient.deleteBookCallable().futureCall(request);
    *   // Do something.
    *   future.get();
@@ -1038,15 +1094,18 @@ public final UnaryCallable<DeleteBookRequest, Empty> deleteBookCallable() {
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   Book book = Book.newBuilder().build();
-   *   Book response = libraryServiceClient.updateBook(book);
+   *   FieldMask updateMask = FieldMask.newBuilder().build();
+   *   Book response = libraryServiceClient.updateBook(book, updateMask);
    * }
    * }</pre>
    *
-   * @param book The book to update with. The name must match or be empty.
+   * @param book The name of the book to update.
+   * @param updateMask Required. Mask of fields to update.
    * @throws com.google.api.gax.rpc.ApiException if the remote call fails
    */
-  public final Book updateBook(Book book) {
-    UpdateBookRequest request = UpdateBookRequest.newBuilder().setBook(book).build();
+  public final Book updateBook(Book book, FieldMask updateMask) {
+    UpdateBookRequest request =
+        UpdateBookRequest.newBuilder().setBook(book).setUpdateMask(updateMask).build();
     return updateBook(request);
   }
 
@@ -1061,8 +1120,8 @@ public final Book updateBook(Book book) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   UpdateBookRequest request =
    *       UpdateBookRequest.newBuilder()
-   *           .setName("name3373707")
    *           .setBook(Book.newBuilder().build())
+   *           .setUpdateMask(FieldMask.newBuilder().build())
    *           .build();
    *   Book response = libraryServiceClient.updateBook(request);
    * }
@@ -1086,8 +1145,8 @@ public final Book updateBook(UpdateBookRequest request) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   UpdateBookRequest request =
    *       UpdateBookRequest.newBuilder()
-   *           .setName("name3373707")
    *           .setBook(Book.newBuilder().build())
+   *           .setUpdateMask(FieldMask.newBuilder().build())
    *           .build();
    *   ApiFuture<Book> future = libraryServiceClient.updateBookCallable().futureCall(request);
    *   // Do something.
@@ -1108,7 +1167,7 @@ public final UnaryCallable<UpdateBookRequest, Book> updateBookCallable() {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+   *   BookName name = BookName.of("[SHELF]", "[BOOK]");
    *   ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
    *   Book response = libraryServiceClient.moveBook(name, otherShelfName);
    * }
@@ -1136,8 +1195,8 @@ public final Book moveBook(BookName name, ShelfName otherShelfName) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
-   *   String otherShelfName = "otherShelfName-1942963547";
+   *   BookName name = BookName.of("[SHELF]", "[BOOK]");
+   *   String otherShelfName = ShelfName.of("[SHELF_ID]").toString();
    *   Book response = libraryServiceClient.moveBook(name, otherShelfName);
    * }
    * }</pre>
@@ -1164,7 +1223,7 @@ public final Book moveBook(BookName name, String otherShelfName) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
+   *   String name = BookName.of("[SHELF]", "[BOOK]").toString();
    *   ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
    *   Book response = libraryServiceClient.moveBook(name, otherShelfName);
    * }
@@ -1192,8 +1251,8 @@ public final Book moveBook(String name, ShelfName otherShelfName) {
    *
    * <pre>{@code
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
-   *   String name = "name3373707";
-   *   String otherShelfName = "otherShelfName-1942963547";
+   *   String name = BookName.of("[SHELF]", "[BOOK]").toString();
+   *   String otherShelfName = ShelfName.of("[SHELF_ID]").toString();
    *   Book response = libraryServiceClient.moveBook(name, otherShelfName);
    * }
    * }</pre>
@@ -1219,8 +1278,8 @@ public final Book moveBook(String name, String otherShelfName) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   MoveBookRequest request =
    *       MoveBookRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setOtherShelfName("otherShelfName-1942963547")
+   *           .setName(BookName.of("[SHELF]", "[BOOK]").toString())
+   *           .setOtherShelfName(ShelfName.of("[SHELF_ID]").toString())
    *           .build();
    *   Book response = libraryServiceClient.moveBook(request);
    * }
@@ -1244,8 +1303,8 @@ public final Book moveBook(MoveBookRequest request) {
    * try (LibraryServiceClient libraryServiceClient = LibraryServiceClient.create()) {
    *   MoveBookRequest request =
    *       MoveBookRequest.newBuilder()
-   *           .setName("name3373707")
-   *           .setOtherShelfName("otherShelfName-1942963547")
+   *           .setName(BookName.of("[SHELF]", "[BOOK]").toString())
+   *           .setOtherShelfName(ShelfName.of("[SHELF_ID]").toString())
    *           .build();
    *   ApiFuture<Book> future = libraryServiceClient.moveBookCallable().futureCall(request);
    *   // Do something.
@@ -1301,14 +1360,7 @@ public static ApiFuture<ListShelvesPagedResponse> createAsync(
       ApiFuture<ListShelvesPage> futurePage =
           ListShelvesPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListShelvesPage, ListShelvesPagedResponse>() {
-            @Override
-            public ListShelvesPagedResponse apply(ListShelvesPage input) {
-              return new ListShelvesPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListShelvesPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListShelvesPagedResponse(ListShelvesPage page) {
@@ -1377,14 +1429,7 @@ public static ApiFuture<ListBooksPagedResponse> createAsync(
       ApiFuture<ListBooksPage> futurePage =
           ListBooksPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListBooksPage, ListBooksPagedResponse>() {
-            @Override
-            public ListBooksPagedResponse apply(ListBooksPage input) {
-              return new ListBooksPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListBooksPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListBooksPagedResponse(ListBooksPage page) {
diff --git a/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClientTest.java b/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClientTest.java
index 82edc829d0..5cc5819105 100644
--- a/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClientTest.java
+++ b/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceClientTest.java
@@ -46,6 +46,7 @@
 import com.google.example.library.v1.UpdateBookRequest;
 import com.google.protobuf.AbstractMessage;
 import com.google.protobuf.Empty;
+import com.google.protobuf.FieldMask;
 import io.grpc.StatusRuntimeException;
 import java.io.IOException;
 import java.util.Arrays;
@@ -61,10 +62,10 @@
 
 @Generated("by gapic-generator-java")
 public class LibraryServiceClientTest {
-  private static MockServiceHelper mockServiceHelper;
-  private LibraryServiceClient client;
   private static MockLibraryService mockLibraryService;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private LibraryServiceClient client;
 
   @BeforeClass
   public static void startStaticServer() {
@@ -345,9 +346,9 @@ public void mergeShelvesTest() throws Exception {
     mockLibraryService.addResponse(expectedResponse);
 
     ShelfName name = ShelfName.of("[SHELF_ID]");
-    ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
+    ShelfName otherShelf = ShelfName.of("[SHELF_ID]");
 
-    Shelf actualResponse = client.mergeShelves(name, otherShelfName);
+    Shelf actualResponse = client.mergeShelves(name, otherShelf);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
@@ -355,7 +356,7 @@ public void mergeShelvesTest() throws Exception {
     MergeShelvesRequest actualRequest = ((MergeShelvesRequest) actualRequests.get(0));
 
     Assert.assertEquals(name.toString(), actualRequest.getName());
-    Assert.assertEquals(otherShelfName.toString(), actualRequest.getOtherShelfName());
+    Assert.assertEquals(otherShelf.toString(), actualRequest.getOtherShelf());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -369,8 +370,8 @@ public void mergeShelvesExceptionTest() throws Exception {
 
     try {
       ShelfName name = ShelfName.of("[SHELF_ID]");
-      ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
-      client.mergeShelves(name, otherShelfName);
+      ShelfName otherShelf = ShelfName.of("[SHELF_ID]");
+      client.mergeShelves(name, otherShelf);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -387,9 +388,9 @@ public void mergeShelvesTest2() throws Exception {
     mockLibraryService.addResponse(expectedResponse);
 
     ShelfName name = ShelfName.of("[SHELF_ID]");
-    String otherShelfName = "otherShelfName-1942963547";
+    String otherShelf = "otherShelf-193668870";
 
-    Shelf actualResponse = client.mergeShelves(name, otherShelfName);
+    Shelf actualResponse = client.mergeShelves(name, otherShelf);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
@@ -397,7 +398,7 @@ public void mergeShelvesTest2() throws Exception {
     MergeShelvesRequest actualRequest = ((MergeShelvesRequest) actualRequests.get(0));
 
     Assert.assertEquals(name.toString(), actualRequest.getName());
-    Assert.assertEquals(otherShelfName, actualRequest.getOtherShelfName());
+    Assert.assertEquals(otherShelf, actualRequest.getOtherShelf());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -411,8 +412,8 @@ public void mergeShelvesExceptionTest2() throws Exception {
 
     try {
       ShelfName name = ShelfName.of("[SHELF_ID]");
-      String otherShelfName = "otherShelfName-1942963547";
-      client.mergeShelves(name, otherShelfName);
+      String otherShelf = "otherShelf-193668870";
+      client.mergeShelves(name, otherShelf);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -429,9 +430,9 @@ public void mergeShelvesTest3() throws Exception {
     mockLibraryService.addResponse(expectedResponse);
 
     String name = "name3373707";
-    ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
+    ShelfName otherShelf = ShelfName.of("[SHELF_ID]");
 
-    Shelf actualResponse = client.mergeShelves(name, otherShelfName);
+    Shelf actualResponse = client.mergeShelves(name, otherShelf);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
@@ -439,7 +440,7 @@ public void mergeShelvesTest3() throws Exception {
     MergeShelvesRequest actualRequest = ((MergeShelvesRequest) actualRequests.get(0));
 
     Assert.assertEquals(name, actualRequest.getName());
-    Assert.assertEquals(otherShelfName.toString(), actualRequest.getOtherShelfName());
+    Assert.assertEquals(otherShelf.toString(), actualRequest.getOtherShelf());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -453,8 +454,8 @@ public void mergeShelvesExceptionTest3() throws Exception {
 
     try {
       String name = "name3373707";
-      ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
-      client.mergeShelves(name, otherShelfName);
+      ShelfName otherShelf = ShelfName.of("[SHELF_ID]");
+      client.mergeShelves(name, otherShelf);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -471,9 +472,9 @@ public void mergeShelvesTest4() throws Exception {
     mockLibraryService.addResponse(expectedResponse);
 
     String name = "name3373707";
-    String otherShelfName = "otherShelfName-1942963547";
+    String otherShelf = "otherShelf-193668870";
 
-    Shelf actualResponse = client.mergeShelves(name, otherShelfName);
+    Shelf actualResponse = client.mergeShelves(name, otherShelf);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
@@ -481,7 +482,7 @@ public void mergeShelvesTest4() throws Exception {
     MergeShelvesRequest actualRequest = ((MergeShelvesRequest) actualRequests.get(0));
 
     Assert.assertEquals(name, actualRequest.getName());
-    Assert.assertEquals(otherShelfName, actualRequest.getOtherShelfName());
+    Assert.assertEquals(otherShelf, actualRequest.getOtherShelf());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -495,8 +496,8 @@ public void mergeShelvesExceptionTest4() throws Exception {
 
     try {
       String name = "name3373707";
-      String otherShelfName = "otherShelfName-1942963547";
-      client.mergeShelves(name, otherShelfName);
+      String otherShelf = "otherShelf-193668870";
+      client.mergeShelves(name, otherShelf);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -507,24 +508,24 @@ public void mergeShelvesExceptionTest4() throws Exception {
   public void createBookTest() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    ShelfName name = ShelfName.of("[SHELF_ID]");
+    ShelfName parent = ShelfName.of("[SHELF_ID]");
     Book book = Book.newBuilder().build();
 
-    Book actualResponse = client.createBook(name, book);
+    Book actualResponse = client.createBook(parent, book);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
     Assert.assertEquals(1, actualRequests.size());
     CreateBookRequest actualRequest = ((CreateBookRequest) actualRequests.get(0));
 
-    Assert.assertEquals(name.toString(), actualRequest.getName());
+    Assert.assertEquals(parent.toString(), actualRequest.getParent());
     Assert.assertEquals(book, actualRequest.getBook());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
@@ -538,9 +539,9 @@ public void createBookExceptionTest() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      ShelfName name = ShelfName.of("[SHELF_ID]");
+      ShelfName parent = ShelfName.of("[SHELF_ID]");
       Book book = Book.newBuilder().build();
-      client.createBook(name, book);
+      client.createBook(parent, book);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -551,24 +552,24 @@ public void createBookExceptionTest() throws Exception {
   public void createBookTest2() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    String name = "name3373707";
+    String parent = "parent-995424086";
     Book book = Book.newBuilder().build();
 
-    Book actualResponse = client.createBook(name, book);
+    Book actualResponse = client.createBook(parent, book);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
     Assert.assertEquals(1, actualRequests.size());
     CreateBookRequest actualRequest = ((CreateBookRequest) actualRequests.get(0));
 
-    Assert.assertEquals(name, actualRequest.getName());
+    Assert.assertEquals(parent, actualRequest.getParent());
     Assert.assertEquals(book, actualRequest.getBook());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
@@ -582,9 +583,9 @@ public void createBookExceptionTest2() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      String name = "name3373707";
+      String parent = "parent-995424086";
       Book book = Book.newBuilder().build();
-      client.createBook(name, book);
+      client.createBook(parent, book);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -595,14 +596,14 @@ public void createBookExceptionTest2() throws Exception {
   public void getBookTest() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+    BookName name = BookName.of("[SHELF]", "[BOOK]");
 
     Book actualResponse = client.getBook(name);
     Assert.assertEquals(expectedResponse, actualResponse);
@@ -624,7 +625,7 @@ public void getBookExceptionTest() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+      BookName name = BookName.of("[SHELF]", "[BOOK]");
       client.getBook(name);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
@@ -636,7 +637,7 @@ public void getBookExceptionTest() throws Exception {
   public void getBookTest2() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
@@ -683,9 +684,9 @@ public void listBooksTest() throws Exception {
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    ShelfName name = ShelfName.of("[SHELF_ID]");
+    ShelfName parent = ShelfName.of("[SHELF_ID]");
 
-    ListBooksPagedResponse pagedListResponse = client.listBooks(name);
+    ListBooksPagedResponse pagedListResponse = client.listBooks(parent);
 
     List<Book> resources = Lists.newArrayList(pagedListResponse.iterateAll());
 
@@ -696,7 +697,7 @@ public void listBooksTest() throws Exception {
     Assert.assertEquals(1, actualRequests.size());
     ListBooksRequest actualRequest = ((ListBooksRequest) actualRequests.get(0));
 
-    Assert.assertEquals(name.toString(), actualRequest.getName());
+    Assert.assertEquals(parent.toString(), actualRequest.getParent());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -709,8 +710,8 @@ public void listBooksExceptionTest() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      ShelfName name = ShelfName.of("[SHELF_ID]");
-      client.listBooks(name);
+      ShelfName parent = ShelfName.of("[SHELF_ID]");
+      client.listBooks(parent);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -727,9 +728,9 @@ public void listBooksTest2() throws Exception {
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    String name = "name3373707";
+    String parent = "parent-995424086";
 
-    ListBooksPagedResponse pagedListResponse = client.listBooks(name);
+    ListBooksPagedResponse pagedListResponse = client.listBooks(parent);
 
     List<Book> resources = Lists.newArrayList(pagedListResponse.iterateAll());
 
@@ -740,7 +741,7 @@ public void listBooksTest2() throws Exception {
     Assert.assertEquals(1, actualRequests.size());
     ListBooksRequest actualRequest = ((ListBooksRequest) actualRequests.get(0));
 
-    Assert.assertEquals(name, actualRequest.getName());
+    Assert.assertEquals(parent, actualRequest.getParent());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -753,8 +754,8 @@ public void listBooksExceptionTest2() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      String name = "name3373707";
-      client.listBooks(name);
+      String parent = "parent-995424086";
+      client.listBooks(parent);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -766,15 +767,15 @@ public void deleteBookTest() throws Exception {
     Empty expectedResponse = Empty.newBuilder().build();
     mockLibraryService.addResponse(expectedResponse);
 
-    DeleteBookRequest request = DeleteBookRequest.newBuilder().setName("name3373707").build();
+    BookName name = BookName.of("[SHELF]", "[BOOK]");
 
-    client.deleteBook(request);
+    client.deleteBook(name);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
     Assert.assertEquals(1, actualRequests.size());
     DeleteBookRequest actualRequest = ((DeleteBookRequest) actualRequests.get(0));
 
-    Assert.assertEquals(request.getName(), actualRequest.getName());
+    Assert.assertEquals(name.toString(), actualRequest.getName());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -787,8 +788,42 @@ public void deleteBookExceptionTest() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      DeleteBookRequest request = DeleteBookRequest.newBuilder().setName("name3373707").build();
-      client.deleteBook(request);
+      BookName name = BookName.of("[SHELF]", "[BOOK]");
+      client.deleteBook(name);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void deleteBookTest2() throws Exception {
+    Empty expectedResponse = Empty.newBuilder().build();
+    mockLibraryService.addResponse(expectedResponse);
+
+    String name = "name3373707";
+
+    client.deleteBook(name);
+
+    List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    DeleteBookRequest actualRequest = ((DeleteBookRequest) actualRequests.get(0));
+
+    Assert.assertEquals(name, actualRequest.getName());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void deleteBookExceptionTest2() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockLibraryService.addException(exception);
+
+    try {
+      String name = "name3373707";
+      client.deleteBook(name);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -799,7 +834,7 @@ public void deleteBookExceptionTest() throws Exception {
   public void updateBookTest() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
@@ -807,8 +842,9 @@ public void updateBookTest() throws Exception {
     mockLibraryService.addResponse(expectedResponse);
 
     Book book = Book.newBuilder().build();
+    FieldMask updateMask = FieldMask.newBuilder().build();
 
-    Book actualResponse = client.updateBook(book);
+    Book actualResponse = client.updateBook(book, updateMask);
     Assert.assertEquals(expectedResponse, actualResponse);
 
     List<AbstractMessage> actualRequests = mockLibraryService.getRequests();
@@ -816,6 +852,7 @@ public void updateBookTest() throws Exception {
     UpdateBookRequest actualRequest = ((UpdateBookRequest) actualRequests.get(0));
 
     Assert.assertEquals(book, actualRequest.getBook());
+    Assert.assertEquals(updateMask, actualRequest.getUpdateMask());
     Assert.assertTrue(
         channelProvider.isHeaderSent(
             ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
@@ -829,7 +866,8 @@ public void updateBookExceptionTest() throws Exception {
 
     try {
       Book book = Book.newBuilder().build();
-      client.updateBook(book);
+      FieldMask updateMask = FieldMask.newBuilder().build();
+      client.updateBook(book, updateMask);
       Assert.fail("No exception raised");
     } catch (InvalidArgumentException e) {
       // Expected exception.
@@ -840,14 +878,14 @@ public void updateBookExceptionTest() throws Exception {
   public void moveBookTest() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+    BookName name = BookName.of("[SHELF]", "[BOOK]");
     ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
 
     Book actualResponse = client.moveBook(name, otherShelfName);
@@ -871,7 +909,7 @@ public void moveBookExceptionTest() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+      BookName name = BookName.of("[SHELF]", "[BOOK]");
       ShelfName otherShelfName = ShelfName.of("[SHELF_ID]");
       client.moveBook(name, otherShelfName);
       Assert.fail("No exception raised");
@@ -884,14 +922,14 @@ public void moveBookExceptionTest() throws Exception {
   public void moveBookTest2() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
             .build();
     mockLibraryService.addResponse(expectedResponse);
 
-    BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+    BookName name = BookName.of("[SHELF]", "[BOOK]");
     String otherShelfName = "otherShelfName-1942963547";
 
     Book actualResponse = client.moveBook(name, otherShelfName);
@@ -915,7 +953,7 @@ public void moveBookExceptionTest2() throws Exception {
     mockLibraryService.addException(exception);
 
     try {
-      BookName name = BookName.of("[SHELF_ID]", "[BOOK_ID]");
+      BookName name = BookName.of("[SHELF]", "[BOOK]");
       String otherShelfName = "otherShelfName-1942963547";
       client.moveBook(name, otherShelfName);
       Assert.fail("No exception raised");
@@ -928,7 +966,7 @@ public void moveBookExceptionTest2() throws Exception {
   public void moveBookTest3() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
@@ -972,7 +1010,7 @@ public void moveBookExceptionTest3() throws Exception {
   public void moveBookTest4() throws Exception {
     Book expectedResponse =
         Book.newBuilder()
-            .setName(BookName.of("[SHELF_ID]", "[BOOK_ID]").toString())
+            .setName(BookName.of("[SHELF]", "[BOOK]").toString())
             .setAuthor("author-1406328437")
             .setTitle("title110371416")
             .setRead(true)
diff --git a/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceSettings.java b/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceSettings.java
index 81c0fb537b..b4d1a7f314 100644
--- a/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceSettings.java
+++ b/test/integration/goldens/library/com/google/cloud/example/library/v1/LibraryServiceSettings.java
@@ -230,14 +230,13 @@ public LibraryServiceStubSettings.Builder getStubSettingsBuilder() {
       return ((LibraryServiceStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/library/com/google/cloud/example/library/v1/gapic_metadata.json b/test/integration/goldens/library/com/google/cloud/example/library/v1/gapic_metadata.json
index 412c5f19c7..b2812fef26 100644
--- a/test/integration/goldens/library/com/google/cloud/example/library/v1/gapic_metadata.json
+++ b/test/integration/goldens/library/com/google/cloud/example/library/v1/gapic_metadata.json
@@ -17,7 +17,7 @@
               "methods": ["createShelf", "createShelf", "createShelfCallable"]
             },
             "DeleteBook": {
-              "methods": ["deleteBook", "deleteBookCallable"]
+              "methods": ["deleteBook", "deleteBook", "deleteBook", "deleteBookCallable"]
             },
             "DeleteShelf": {
               "methods": ["deleteShelf", "deleteShelf", "deleteShelf", "deleteShelfCallable"]
diff --git a/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/GrpcLibraryServiceStub.java b/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/GrpcLibraryServiceStub.java
index 3e09a011a6..d1ff40a058 100644
--- a/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/GrpcLibraryServiceStub.java
+++ b/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/GrpcLibraryServiceStub.java
@@ -24,7 +24,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.example.library.v1.Book;
@@ -217,13 +216,10 @@ protected GrpcLibraryServiceStub(
         GrpcCallSettings.<GetShelfRequest, Shelf>newBuilder()
             .setMethodDescriptor(getShelfMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetShelfRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetShelfRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListShelvesRequest, ListShelvesResponse> listShelvesTransportSettings =
@@ -234,104 +230,80 @@ public Map<String, String> extract(GetShelfRequest request) {
         GrpcCallSettings.<DeleteShelfRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteShelfMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteShelfRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteShelfRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<MergeShelvesRequest, Shelf> mergeShelvesTransportSettings =
         GrpcCallSettings.<MergeShelvesRequest, Shelf>newBuilder()
             .setMethodDescriptor(mergeShelvesMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<MergeShelvesRequest>() {
-                  @Override
-                  public Map<String, String> extract(MergeShelvesRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateBookRequest, Book> createBookTransportSettings =
         GrpcCallSettings.<CreateBookRequest, Book>newBuilder()
             .setMethodDescriptor(createBookMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateBookRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateBookRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetBookRequest, Book> getBookTransportSettings =
         GrpcCallSettings.<GetBookRequest, Book>newBuilder()
             .setMethodDescriptor(getBookMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetBookRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetBookRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListBooksRequest, ListBooksResponse> listBooksTransportSettings =
         GrpcCallSettings.<ListBooksRequest, ListBooksResponse>newBuilder()
             .setMethodDescriptor(listBooksMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListBooksRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListBooksRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteBookRequest, Empty> deleteBookTransportSettings =
         GrpcCallSettings.<DeleteBookRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteBookMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteBookRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteBookRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateBookRequest, Book> updateBookTransportSettings =
         GrpcCallSettings.<UpdateBookRequest, Book>newBuilder()
             .setMethodDescriptor(updateBookMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateBookRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateBookRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("book.name", String.valueOf(request.getBook().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("book.name", String.valueOf(request.getBook().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<MoveBookRequest, Book> moveBookTransportSettings =
         GrpcCallSettings.<MoveBookRequest, Book>newBuilder()
             .setMethodDescriptor(moveBookMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<MoveBookRequest>() {
-                  @Override
-                  public Map<String, String> extract(MoveBookRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
 
@@ -450,7 +422,13 @@ public UnaryCallable<MoveBookRequest, Book> moveBookCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/LibraryServiceStubSettings.java b/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/LibraryServiceStubSettings.java
index 0f7a252975..159cd561a6 100644
--- a/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/LibraryServiceStubSettings.java
+++ b/test/integration/goldens/library/com/google/cloud/example/library/v1/stub/LibraryServiceStubSettings.java
@@ -64,6 +64,7 @@
 import java.io.IOException;
 import java.util.List;
 import javax.annotation.Generated;
+import org.threeten.bp.Duration;
 
 // AUTO-GENERATED DOCUMENTATION AND CLASS.
 /**
@@ -303,6 +304,11 @@ public static String getDefaultEndpoint() {
     return "library-example.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "library-example.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -310,7 +316,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -387,7 +395,13 @@ public static class Builder extends StubSettings.Builder<LibraryServiceStubSetti
     static {
       ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
           ImmutableMap.builder();
-      definitions.put("no_retry_codes", ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList()));
+      definitions.put(
+          "retry_policy_1_codes", ImmutableSet.copyOf(Lists.<StatusCode.Code>newArrayList()));
+      definitions.put(
+          "retry_policy_0_codes",
+          ImmutableSet.copyOf(
+              Lists.<StatusCode.Code>newArrayList(
+                  StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
       RETRYABLE_CODE_DEFINITIONS = definitions.build();
     }
 
@@ -396,8 +410,28 @@ public static class Builder extends StubSettings.Builder<LibraryServiceStubSetti
     static {
       ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
       RetrySettings settings = null;
-      settings = RetrySettings.newBuilder().setRpcTimeoutMultiplier(1.0).build();
-      definitions.put("no_retry_params", settings);
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRetryDelay(Duration.ofMillis(100L))
+              .setRetryDelayMultiplier(1.3)
+              .setMaxRetryDelay(Duration.ofMillis(60000L))
+              .setInitialRpcTimeout(Duration.ofMillis(60000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(60000L))
+              .setTotalTimeout(Duration.ofMillis(60000L))
+              .build();
+      definitions.put("retry_policy_1_params", settings);
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRetryDelay(Duration.ofMillis(100L))
+              .setRetryDelayMultiplier(1.3)
+              .setMaxRetryDelay(Duration.ofMillis(60000L))
+              .setInitialRpcTimeout(Duration.ofMillis(60000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(60000L))
+              .setTotalTimeout(Duration.ofMillis(60000L))
+              .build();
+      definitions.put("retry_policy_0_params", settings);
       RETRY_PARAM_DEFINITIONS = definitions.build();
     }
 
@@ -473,6 +507,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -480,70 +516,69 @@ private static Builder createDefault() {
     private static Builder initDefaults(Builder builder) {
       builder
           .createShelfSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_1_params"));
 
       builder
           .getShelfSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .listShelvesSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .deleteShelfSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .mergeShelvesSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_1_params"));
 
       builder
           .createBookSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_1_params"));
 
       builder
           .getBookSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .listBooksSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .deleteBookSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .updateBookSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
 
       builder
           .moveBookSettings()
-          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("no_retry_codes"))
-          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("no_retry_params"));
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_1_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_1_params"));
 
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/library/com/google/example/library/v1/BookName.java b/test/integration/goldens/library/com/google/example/library/v1/BookName.java
index a79c744949..1352d23cc9 100644
--- a/test/integration/goldens/library/com/google/example/library/v1/BookName.java
+++ b/test/integration/goldens/library/com/google/example/library/v1/BookName.java
@@ -29,29 +29,29 @@
 // AUTO-GENERATED DOCUMENTATION AND CLASS.
 @Generated("by gapic-generator-java")
 public class BookName implements ResourceName {
-  private static final PathTemplate SHELF_ID_BOOK_ID =
-      PathTemplate.createWithoutUrlEncoding("shelves/{shelf_id}/books/{book_id}");
+  private static final PathTemplate SHELF_BOOK =
+      PathTemplate.createWithoutUrlEncoding("shelves/{shelf}/books/{book}");
   private volatile Map<String, String> fieldValuesMap;
-  private final String shelfId;
-  private final String bookId;
+  private final String shelf;
+  private final String book;
 
   @Deprecated
   protected BookName() {
-    shelfId = null;
-    bookId = null;
+    shelf = null;
+    book = null;
   }
 
   private BookName(Builder builder) {
-    shelfId = Preconditions.checkNotNull(builder.getShelfId());
-    bookId = Preconditions.checkNotNull(builder.getBookId());
+    shelf = Preconditions.checkNotNull(builder.getShelf());
+    book = Preconditions.checkNotNull(builder.getBook());
   }
 
-  public String getShelfId() {
-    return shelfId;
+  public String getShelf() {
+    return shelf;
   }
 
-  public String getBookId() {
-    return bookId;
+  public String getBook() {
+    return book;
   }
 
   public static Builder newBuilder() {
@@ -62,12 +62,12 @@ public Builder toBuilder() {
     return new Builder(this);
   }
 
-  public static BookName of(String shelfId, String bookId) {
-    return newBuilder().setShelfId(shelfId).setBookId(bookId).build();
+  public static BookName of(String shelf, String book) {
+    return newBuilder().setShelf(shelf).setBook(book).build();
   }
 
-  public static String format(String shelfId, String bookId) {
-    return newBuilder().setShelfId(shelfId).setBookId(bookId).build().toString();
+  public static String format(String shelf, String book) {
+    return newBuilder().setShelf(shelf).setBook(book).build().toString();
   }
 
   public static BookName parse(String formattedString) {
@@ -75,9 +75,9 @@ public static BookName parse(String formattedString) {
       return null;
     }
     Map<String, String> matchMap =
-        SHELF_ID_BOOK_ID.validatedMatch(
+        SHELF_BOOK.validatedMatch(
             formattedString, "BookName.parse: formattedString not in valid format");
-    return of(matchMap.get("shelf_id"), matchMap.get("book_id"));
+    return of(matchMap.get("shelf"), matchMap.get("book"));
   }
 
   public static List<BookName> parseList(List<String> formattedStrings) {
@@ -101,7 +101,7 @@ public static List<String> toStringList(List<BookName> values) {
   }
 
   public static boolean isParsableFrom(String formattedString) {
-    return SHELF_ID_BOOK_ID.matches(formattedString);
+    return SHELF_BOOK.matches(formattedString);
   }
 
   @Override
@@ -110,11 +110,11 @@ public Map<String, String> getFieldValuesMap() {
       synchronized (this) {
         if (fieldValuesMap == null) {
           ImmutableMap.Builder<String, String> fieldMapBuilder = ImmutableMap.builder();
-          if (shelfId != null) {
-            fieldMapBuilder.put("shelf_id", shelfId);
+          if (shelf != null) {
+            fieldMapBuilder.put("shelf", shelf);
           }
-          if (bookId != null) {
-            fieldMapBuilder.put("book_id", bookId);
+          if (book != null) {
+            fieldMapBuilder.put("book", book);
           }
           fieldValuesMap = fieldMapBuilder.build();
         }
@@ -129,7 +129,7 @@ public String getFieldValue(String fieldName) {
 
   @Override
   public String toString() {
-    return SHELF_ID_BOOK_ID.instantiate("shelf_id", shelfId, "book_id", bookId);
+    return SHELF_BOOK.instantiate("shelf", shelf, "book", book);
   }
 
   @Override
@@ -139,7 +139,7 @@ public boolean equals(Object o) {
     }
     if (o != null || getClass() == o.getClass()) {
       BookName that = ((BookName) o);
-      return Objects.equals(this.shelfId, that.shelfId) && Objects.equals(this.bookId, that.bookId);
+      return Objects.equals(this.shelf, that.shelf) && Objects.equals(this.book, that.book);
     }
     return false;
   }
@@ -148,40 +148,40 @@ public boolean equals(Object o) {
   public int hashCode() {
     int h = 1;
     h *= 1000003;
-    h ^= Objects.hashCode(shelfId);
+    h ^= Objects.hashCode(shelf);
     h *= 1000003;
-    h ^= Objects.hashCode(bookId);
+    h ^= Objects.hashCode(book);
     return h;
   }
 
-  /** Builder for shelves/{shelf_id}/books/{book_id}. */
+  /** Builder for shelves/{shelf}/books/{book}. */
   public static class Builder {
-    private String shelfId;
-    private String bookId;
+    private String shelf;
+    private String book;
 
     protected Builder() {}
 
-    public String getShelfId() {
-      return shelfId;
+    public String getShelf() {
+      return shelf;
     }
 
-    public String getBookId() {
-      return bookId;
+    public String getBook() {
+      return book;
     }
 
-    public Builder setShelfId(String shelfId) {
-      this.shelfId = shelfId;
+    public Builder setShelf(String shelf) {
+      this.shelf = shelf;
       return this;
     }
 
-    public Builder setBookId(String bookId) {
-      this.bookId = bookId;
+    public Builder setBook(String book) {
+      this.book = book;
       return this;
     }
 
     private Builder(BookName bookName) {
-      shelfId = bookName.shelfId;
-      bookId = bookName.bookId;
+      this.shelf = bookName.shelf;
+      this.book = bookName.book;
     }
 
     public BookName build() {
diff --git a/test/integration/goldens/library/com/google/example/library/v1/ShelfName.java b/test/integration/goldens/library/com/google/example/library/v1/ShelfName.java
index 594e83f032..f4d226c9e0 100644
--- a/test/integration/goldens/library/com/google/example/library/v1/ShelfName.java
+++ b/test/integration/goldens/library/com/google/example/library/v1/ShelfName.java
@@ -158,7 +158,7 @@ public Builder setShelfId(String shelfId) {
     }
 
     private Builder(ShelfName shelfName) {
-      shelfId = shelfName.shelfId;
+      this.shelfId = shelfName.shelfId;
     }
 
     public ShelfName build() {
diff --git a/test/integration/goldens/logging/BUILD.bazel b/test/integration/goldens/logging/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/logging/BUILD.bazel
+++ b/test/integration/goldens/logging/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClient.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClient.java
index 2ac4343fd8..2bce0705f4 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClient.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.logging.v2;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -2855,14 +2854,7 @@ public static ApiFuture<ListBucketsPagedResponse> createAsync(
       ApiFuture<ListBucketsPage> futurePage =
           ListBucketsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListBucketsPage, ListBucketsPagedResponse>() {
-            @Override
-            public ListBucketsPagedResponse apply(ListBucketsPage input) {
-              return new ListBucketsPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListBucketsPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListBucketsPagedResponse(ListBucketsPage page) {
@@ -2935,14 +2927,7 @@ public static ApiFuture<ListViewsPagedResponse> createAsync(
       ApiFuture<ListViewsPage> futurePage =
           ListViewsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListViewsPage, ListViewsPagedResponse>() {
-            @Override
-            public ListViewsPagedResponse apply(ListViewsPage input) {
-              return new ListViewsPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListViewsPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListViewsPagedResponse(ListViewsPage page) {
@@ -3015,14 +3000,7 @@ public static ApiFuture<ListSinksPagedResponse> createAsync(
       ApiFuture<ListSinksPage> futurePage =
           ListSinksPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListSinksPage, ListSinksPagedResponse>() {
-            @Override
-            public ListSinksPagedResponse apply(ListSinksPage input) {
-              return new ListSinksPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListSinksPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListSinksPagedResponse(ListSinksPage page) {
@@ -3096,12 +3074,7 @@ public static ApiFuture<ListExclusionsPagedResponse> createAsync(
           ListExclusionsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListExclusionsPage, ListExclusionsPagedResponse>() {
-            @Override
-            public ListExclusionsPagedResponse apply(ListExclusionsPage input) {
-              return new ListExclusionsPagedResponse(input);
-            }
-          },
+          input -> new ListExclusionsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClientTest.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClientTest.java
index 442b83c86b..f38bbc6eb5 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClientTest.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigClientTest.java
@@ -95,10 +95,10 @@
 
 @Generated("by gapic-generator-java")
 public class ConfigClientTest {
+  private static MockConfigServiceV2 mockConfigServiceV2;
   private static MockServiceHelper mockServiceHelper;
-  private ConfigClient client;
   private LocalChannelProvider channelProvider;
-  private static MockConfigServiceV2 mockConfigServiceV2;
+  private ConfigClient client;
 
   @BeforeClass
   public static void startStaticServer() {
@@ -1107,7 +1107,7 @@ public void getSinkTest() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1154,7 +1154,7 @@ public void getSinkTest2() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1201,7 +1201,7 @@ public void createSinkTest() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1251,7 +1251,7 @@ public void createSinkTest2() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1301,7 +1301,7 @@ public void createSinkTest3() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1351,7 +1351,7 @@ public void createSinkTest4() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1401,7 +1401,7 @@ public void createSinkTest5() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1451,7 +1451,7 @@ public void updateSinkTest() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1501,7 +1501,7 @@ public void updateSinkTest2() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1551,7 +1551,7 @@ public void updateSinkTest3() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
@@ -1604,7 +1604,7 @@ public void updateSinkTest4() throws Exception {
     LogSink expectedResponse =
         LogSink.newBuilder()
             .setName(LogSinkName.ofProjectSinkName("[PROJECT]", "[SINK]").toString())
-            .setDestination(FolderLocationName.of("[FOLDER]", "[LOCATION]").toString())
+            .setDestination("destination-1429847026")
             .setFilter("filter-1274492040")
             .setDescription("description-1724546052")
             .setDisabled(true)
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigSettings.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigSettings.java
index 8cf51ceae7..1c57850ec1 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigSettings.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/ConfigSettings.java
@@ -309,14 +309,13 @@ public ConfigServiceV2StubSettings.Builder getStubSettingsBuilder() {
       return ((ConfigServiceV2StubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClient.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClient.java
index 66f7afcda2..759c5d2c86 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClient.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClient.java
@@ -18,7 +18,6 @@
 
 import com.google.api.MonitoredResource;
 import com.google.api.MonitoredResourceDescriptor;
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -1032,12 +1031,7 @@ public static ApiFuture<ListLogEntriesPagedResponse> createAsync(
           ListLogEntriesPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListLogEntriesPage, ListLogEntriesPagedResponse>() {
-            @Override
-            public ListLogEntriesPagedResponse apply(ListLogEntriesPage input) {
-              return new ListLogEntriesPagedResponse(input);
-            }
-          },
+          input -> new ListLogEntriesPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -1118,15 +1112,7 @@ public static ApiFuture<ListMonitoredResourceDescriptorsPagedResponse> createAsy
               .createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<
-              ListMonitoredResourceDescriptorsPage,
-              ListMonitoredResourceDescriptorsPagedResponse>() {
-            @Override
-            public ListMonitoredResourceDescriptorsPagedResponse apply(
-                ListMonitoredResourceDescriptorsPage input) {
-              return new ListMonitoredResourceDescriptorsPagedResponse(input);
-            }
-          },
+          input -> new ListMonitoredResourceDescriptorsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -1214,14 +1200,7 @@ public static ApiFuture<ListLogsPagedResponse> createAsync(
       ApiFuture<ListLogsPage> futurePage =
           ListLogsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListLogsPage, ListLogsPagedResponse>() {
-            @Override
-            public ListLogsPagedResponse apply(ListLogsPage input) {
-              return new ListLogsPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListLogsPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListLogsPagedResponse(ListLogsPage page) {
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClientTest.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClientTest.java
index a6395714c6..34c69dc87b 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClientTest.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingClientTest.java
@@ -73,10 +73,10 @@
 
 @Generated("by gapic-generator-java")
 public class LoggingClientTest {
-  private static MockServiceHelper mockServiceHelper;
   private static MockLoggingServiceV2 mockLoggingServiceV2;
-  private LoggingClient client;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private LoggingClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingSettings.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingSettings.java
index c27146d88f..f7bba757b0 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingSettings.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/LoggingSettings.java
@@ -209,14 +209,13 @@ public LoggingServiceV2StubSettings.Builder getStubSettingsBuilder() {
       return ((LoggingServiceV2StubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClient.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClient.java
index 987083a264..e1fdf43653 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClient.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.logging.v2;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -734,12 +733,7 @@ public static ApiFuture<ListLogMetricsPagedResponse> createAsync(
           ListLogMetricsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListLogMetricsPage, ListLogMetricsPagedResponse>() {
-            @Override
-            public ListLogMetricsPagedResponse apply(ListLogMetricsPage input) {
-              return new ListLogMetricsPagedResponse(input);
-            }
-          },
+          input -> new ListLogMetricsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClientTest.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClientTest.java
index e26c9980fb..a81e0368a8 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClientTest.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsClientTest.java
@@ -56,10 +56,10 @@
 
 @Generated("by gapic-generator-java")
 public class MetricsClientTest {
-  private static MockServiceHelper mockServiceHelper;
-  private MetricsClient client;
   private static MockMetricsServiceV2 mockMetricsServiceV2;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private MetricsClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsSettings.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsSettings.java
index 4a4800e90a..1b7765bda7 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsSettings.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/MetricsSettings.java
@@ -188,14 +188,13 @@ public MetricsServiceV2StubSettings.Builder getStubSettingsBuilder() {
       return ((MetricsServiceV2StubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java
index bfeba9f0a4..faf8137eea 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/ConfigServiceV2StubSettings.java
@@ -514,6 +514,11 @@ public static String getDefaultEndpoint() {
     return "logging.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "logging.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -521,7 +526,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -792,6 +799,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -915,14 +924,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcConfigServiceV2Stub.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcConfigServiceV2Stub.java
index 91ddb14f6a..34a747bca2 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcConfigServiceV2Stub.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcConfigServiceV2Stub.java
@@ -26,7 +26,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.logging.v2.CmekSettings;
@@ -362,208 +361,160 @@ protected GrpcConfigServiceV2Stub(
         GrpcCallSettings.<ListBucketsRequest, ListBucketsResponse>newBuilder()
             .setMethodDescriptor(listBucketsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListBucketsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListBucketsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetBucketRequest, LogBucket> getBucketTransportSettings =
         GrpcCallSettings.<GetBucketRequest, LogBucket>newBuilder()
             .setMethodDescriptor(getBucketMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetBucketRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetBucketRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateBucketRequest, LogBucket> createBucketTransportSettings =
         GrpcCallSettings.<CreateBucketRequest, LogBucket>newBuilder()
             .setMethodDescriptor(createBucketMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateBucketRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateBucketRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateBucketRequest, LogBucket> updateBucketTransportSettings =
         GrpcCallSettings.<UpdateBucketRequest, LogBucket>newBuilder()
             .setMethodDescriptor(updateBucketMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateBucketRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateBucketRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteBucketRequest, Empty> deleteBucketTransportSettings =
         GrpcCallSettings.<DeleteBucketRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteBucketMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteBucketRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteBucketRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UndeleteBucketRequest, Empty> undeleteBucketTransportSettings =
         GrpcCallSettings.<UndeleteBucketRequest, Empty>newBuilder()
             .setMethodDescriptor(undeleteBucketMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UndeleteBucketRequest>() {
-                  @Override
-                  public Map<String, String> extract(UndeleteBucketRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListViewsRequest, ListViewsResponse> listViewsTransportSettings =
         GrpcCallSettings.<ListViewsRequest, ListViewsResponse>newBuilder()
             .setMethodDescriptor(listViewsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListViewsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListViewsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetViewRequest, LogView> getViewTransportSettings =
         GrpcCallSettings.<GetViewRequest, LogView>newBuilder()
             .setMethodDescriptor(getViewMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetViewRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetViewRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateViewRequest, LogView> createViewTransportSettings =
         GrpcCallSettings.<CreateViewRequest, LogView>newBuilder()
             .setMethodDescriptor(createViewMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateViewRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateViewRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateViewRequest, LogView> updateViewTransportSettings =
         GrpcCallSettings.<UpdateViewRequest, LogView>newBuilder()
             .setMethodDescriptor(updateViewMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateViewRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateViewRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteViewRequest, Empty> deleteViewTransportSettings =
         GrpcCallSettings.<DeleteViewRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteViewMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteViewRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteViewRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListSinksRequest, ListSinksResponse> listSinksTransportSettings =
         GrpcCallSettings.<ListSinksRequest, ListSinksResponse>newBuilder()
             .setMethodDescriptor(listSinksMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListSinksRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListSinksRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetSinkRequest, LogSink> getSinkTransportSettings =
         GrpcCallSettings.<GetSinkRequest, LogSink>newBuilder()
             .setMethodDescriptor(getSinkMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetSinkRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetSinkRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("sink_name", String.valueOf(request.getSinkName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("sink_name", String.valueOf(request.getSinkName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateSinkRequest, LogSink> createSinkTransportSettings =
         GrpcCallSettings.<CreateSinkRequest, LogSink>newBuilder()
             .setMethodDescriptor(createSinkMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateSinkRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateSinkRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateSinkRequest, LogSink> updateSinkTransportSettings =
         GrpcCallSettings.<UpdateSinkRequest, LogSink>newBuilder()
             .setMethodDescriptor(updateSinkMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateSinkRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateSinkRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("sink_name", String.valueOf(request.getSinkName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("sink_name", String.valueOf(request.getSinkName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteSinkRequest, Empty> deleteSinkTransportSettings =
         GrpcCallSettings.<DeleteSinkRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteSinkMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteSinkRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteSinkRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("sink_name", String.valueOf(request.getSinkName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("sink_name", String.valueOf(request.getSinkName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListExclusionsRequest, ListExclusionsResponse>
@@ -571,91 +522,70 @@ public Map<String, String> extract(DeleteSinkRequest request) {
             GrpcCallSettings.<ListExclusionsRequest, ListExclusionsResponse>newBuilder()
                 .setMethodDescriptor(listExclusionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListExclusionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListExclusionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetExclusionRequest, LogExclusion> getExclusionTransportSettings =
         GrpcCallSettings.<GetExclusionRequest, LogExclusion>newBuilder()
             .setMethodDescriptor(getExclusionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetExclusionRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetExclusionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateExclusionRequest, LogExclusion> createExclusionTransportSettings =
         GrpcCallSettings.<CreateExclusionRequest, LogExclusion>newBuilder()
             .setMethodDescriptor(createExclusionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateExclusionRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateExclusionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateExclusionRequest, LogExclusion> updateExclusionTransportSettings =
         GrpcCallSettings.<UpdateExclusionRequest, LogExclusion>newBuilder()
             .setMethodDescriptor(updateExclusionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateExclusionRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateExclusionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteExclusionRequest, Empty> deleteExclusionTransportSettings =
         GrpcCallSettings.<DeleteExclusionRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteExclusionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteExclusionRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteExclusionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetCmekSettingsRequest, CmekSettings> getCmekSettingsTransportSettings =
         GrpcCallSettings.<GetCmekSettingsRequest, CmekSettings>newBuilder()
             .setMethodDescriptor(getCmekSettingsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetCmekSettingsRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetCmekSettingsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateCmekSettingsRequest, CmekSettings> updateCmekSettingsTransportSettings =
         GrpcCallSettings.<UpdateCmekSettingsRequest, CmekSettings>newBuilder()
             .setMethodDescriptor(updateCmekSettingsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateCmekSettingsRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateCmekSettingsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
 
@@ -889,7 +819,13 @@ public UnaryCallable<UpdateCmekSettingsRequest, CmekSettings> updateCmekSettings
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcLoggingServiceV2Stub.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcLoggingServiceV2Stub.java
index feb0ed3086..c7ce0b40f2 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcLoggingServiceV2Stub.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcLoggingServiceV2Stub.java
@@ -26,7 +26,6 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.BidiStreamingCallable;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.logging.v2.DeleteLogRequest;
@@ -189,13 +188,10 @@ protected GrpcLoggingServiceV2Stub(
         GrpcCallSettings.<DeleteLogRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteLogMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteLogRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteLogRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("log_name", String.valueOf(request.getLogName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("log_name", String.valueOf(request.getLogName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<WriteLogEntriesRequest, WriteLogEntriesResponse>
@@ -220,13 +216,10 @@ public Map<String, String> extract(DeleteLogRequest request) {
         GrpcCallSettings.<ListLogsRequest, ListLogsResponse>newBuilder()
             .setMethodDescriptor(listLogsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListLogsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListLogsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<TailLogEntriesRequest, TailLogEntriesResponse>
@@ -328,7 +321,13 @@ public UnaryCallable<ListLogsRequest, ListLogsPagedResponse> listLogsPagedCallab
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcMetricsServiceV2Stub.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcMetricsServiceV2Stub.java
index fe15cf6052..0fda0bb3db 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcMetricsServiceV2Stub.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/GrpcMetricsServiceV2Stub.java
@@ -23,7 +23,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.logging.v2.CreateLogMetricRequest;
@@ -157,65 +156,50 @@ protected GrpcMetricsServiceV2Stub(
             GrpcCallSettings.<ListLogMetricsRequest, ListLogMetricsResponse>newBuilder()
                 .setMethodDescriptor(listLogMetricsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListLogMetricsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListLogMetricsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<GetLogMetricRequest, LogMetric> getLogMetricTransportSettings =
         GrpcCallSettings.<GetLogMetricRequest, LogMetric>newBuilder()
             .setMethodDescriptor(getLogMetricMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetLogMetricRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetLogMetricRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("metric_name", String.valueOf(request.getMetricName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("metric_name", String.valueOf(request.getMetricName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateLogMetricRequest, LogMetric> createLogMetricTransportSettings =
         GrpcCallSettings.<CreateLogMetricRequest, LogMetric>newBuilder()
             .setMethodDescriptor(createLogMetricMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateLogMetricRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateLogMetricRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateLogMetricRequest, LogMetric> updateLogMetricTransportSettings =
         GrpcCallSettings.<UpdateLogMetricRequest, LogMetric>newBuilder()
             .setMethodDescriptor(updateLogMetricMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateLogMetricRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateLogMetricRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("metric_name", String.valueOf(request.getMetricName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("metric_name", String.valueOf(request.getMetricName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteLogMetricRequest, Empty> deleteLogMetricTransportSettings =
         GrpcCallSettings.<DeleteLogMetricRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteLogMetricMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteLogMetricRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteLogMetricRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("metric_name", String.valueOf(request.getMetricName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("metric_name", String.valueOf(request.getMetricName()));
+                  return params.build();
                 })
             .build();
 
@@ -279,7 +263,13 @@ public UnaryCallable<DeleteLogMetricRequest, Empty> deleteLogMetricCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java
index d1fa3db875..3f3b507702 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/LoggingServiceV2StubSettings.java
@@ -444,6 +444,11 @@ public static String getDefaultEndpoint() {
     return "logging.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "logging.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -451,7 +456,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -626,6 +633,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -675,14 +684,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java
index 3fd951caa0..3cf4be8d73 100644
--- a/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java
+++ b/test/integration/goldens/logging/com/google/cloud/logging/v2/stub/MetricsServiceV2StubSettings.java
@@ -212,6 +212,11 @@ public static String getDefaultEndpoint() {
     return "logging.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "logging.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -219,7 +224,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -371,6 +378,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -404,14 +413,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/logging/com/google/logging/v2/BillingAccountLocationName.java b/test/integration/goldens/logging/com/google/logging/v2/BillingAccountLocationName.java
index 0201fe9765..d2b9e2c050 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/BillingAccountLocationName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/BillingAccountLocationName.java
@@ -184,8 +184,8 @@ public Builder setLocation(String location) {
     }
 
     private Builder(BillingAccountLocationName billingAccountLocationName) {
-      billingAccount = billingAccountLocationName.billingAccount;
-      location = billingAccountLocationName.location;
+      this.billingAccount = billingAccountLocationName.billingAccount;
+      this.location = billingAccountLocationName.location;
     }
 
     public BillingAccountLocationName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/BillingAccountName.java b/test/integration/goldens/logging/com/google/logging/v2/BillingAccountName.java
index 42f46677c4..b6d13b3b2e 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/BillingAccountName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/BillingAccountName.java
@@ -158,7 +158,7 @@ public Builder setBillingAccount(String billingAccount) {
     }
 
     private Builder(BillingAccountName billingAccountName) {
-      billingAccount = billingAccountName.billingAccount;
+      this.billingAccount = billingAccountName.billingAccount;
     }
 
     public BillingAccountName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/CmekSettingsName.java b/test/integration/goldens/logging/com/google/logging/v2/CmekSettingsName.java
index 60f7b73860..8992813529 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/CmekSettingsName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/CmekSettingsName.java
@@ -310,7 +310,7 @@ private Builder(CmekSettingsName cmekSettingsName) {
       Preconditions.checkArgument(
           Objects.equals(cmekSettingsName.pathTemplate, PROJECT),
           "toBuilder is only supported when CmekSettingsName has the pattern of projects/{project}/cmekSettings");
-      project = cmekSettingsName.project;
+      this.project = cmekSettingsName.project;
     }
 
     public CmekSettingsName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/FolderLocationName.java b/test/integration/goldens/logging/com/google/logging/v2/FolderLocationName.java
index c380821f0e..08cca56bc8 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/FolderLocationName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/FolderLocationName.java
@@ -181,8 +181,8 @@ public Builder setLocation(String location) {
     }
 
     private Builder(FolderLocationName folderLocationName) {
-      folder = folderLocationName.folder;
-      location = folderLocationName.location;
+      this.folder = folderLocationName.folder;
+      this.location = folderLocationName.location;
     }
 
     public FolderLocationName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/FolderName.java b/test/integration/goldens/logging/com/google/logging/v2/FolderName.java
index 4da442ed84..8b76cb8fcb 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/FolderName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/FolderName.java
@@ -158,7 +158,7 @@ public Builder setFolder(String folder) {
     }
 
     private Builder(FolderName folderName) {
-      folder = folderName.folder;
+      this.folder = folderName.folder;
     }
 
     public FolderName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LocationName.java b/test/integration/goldens/logging/com/google/logging/v2/LocationName.java
index 18069bd08d..6fce45d9d7 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LocationName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LocationName.java
@@ -181,8 +181,8 @@ public Builder setLocation(String location) {
     }
 
     private Builder(LocationName locationName) {
-      project = locationName.project;
-      location = locationName.location;
+      this.project = locationName.project;
+      this.location = locationName.location;
     }
 
     public LocationName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LogBucketName.java b/test/integration/goldens/logging/com/google/logging/v2/LogBucketName.java
index c373feeea0..7dcdc6bc2f 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LogBucketName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LogBucketName.java
@@ -415,9 +415,9 @@ private Builder(LogBucketName logBucketName) {
       Preconditions.checkArgument(
           Objects.equals(logBucketName.pathTemplate, PROJECT_LOCATION_BUCKET),
           "toBuilder is only supported when LogBucketName has the pattern of projects/{project}/locations/{location}/buckets/{bucket}");
-      project = logBucketName.project;
-      location = logBucketName.location;
-      bucket = logBucketName.bucket;
+      this.project = logBucketName.project;
+      this.location = logBucketName.location;
+      this.bucket = logBucketName.bucket;
     }
 
     public LogBucketName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LogExclusionName.java b/test/integration/goldens/logging/com/google/logging/v2/LogExclusionName.java
index 04bf413562..71b6aca5a7 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LogExclusionName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LogExclusionName.java
@@ -354,8 +354,8 @@ private Builder(LogExclusionName logExclusionName) {
       Preconditions.checkArgument(
           Objects.equals(logExclusionName.pathTemplate, PROJECT_EXCLUSION),
           "toBuilder is only supported when LogExclusionName has the pattern of projects/{project}/exclusions/{exclusion}");
-      project = logExclusionName.project;
-      exclusion = logExclusionName.exclusion;
+      this.project = logExclusionName.project;
+      this.exclusion = logExclusionName.exclusion;
     }
 
     public LogExclusionName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LogMetricName.java b/test/integration/goldens/logging/com/google/logging/v2/LogMetricName.java
index cbeb10b808..f271ecf0c8 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LogMetricName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LogMetricName.java
@@ -180,8 +180,8 @@ public Builder setMetric(String metric) {
     }
 
     private Builder(LogMetricName logMetricName) {
-      project = logMetricName.project;
-      metric = logMetricName.metric;
+      this.project = logMetricName.project;
+      this.metric = logMetricName.metric;
     }
 
     public LogMetricName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LogName.java b/test/integration/goldens/logging/com/google/logging/v2/LogName.java
index af30905c73..056e80cc85 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LogName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LogName.java
@@ -340,8 +340,8 @@ private Builder(LogName logName) {
       Preconditions.checkArgument(
           Objects.equals(logName.pathTemplate, PROJECT_LOG),
           "toBuilder is only supported when LogName has the pattern of projects/{project}/logs/{log}");
-      project = logName.project;
-      log = logName.log;
+      this.project = logName.project;
+      this.log = logName.log;
     }
 
     public LogName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LogSinkName.java b/test/integration/goldens/logging/com/google/logging/v2/LogSinkName.java
index efef17874b..6fcfb8a2f3 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LogSinkName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LogSinkName.java
@@ -344,8 +344,8 @@ private Builder(LogSinkName logSinkName) {
       Preconditions.checkArgument(
           Objects.equals(logSinkName.pathTemplate, PROJECT_SINK),
           "toBuilder is only supported when LogSinkName has the pattern of projects/{project}/sinks/{sink}");
-      project = logSinkName.project;
-      sink = logSinkName.sink;
+      this.project = logSinkName.project;
+      this.sink = logSinkName.sink;
     }
 
     public LogSinkName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/LogViewName.java b/test/integration/goldens/logging/com/google/logging/v2/LogViewName.java
index 3875d5c5c4..85788f7444 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/LogViewName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/LogViewName.java
@@ -472,10 +472,10 @@ private Builder(LogViewName logViewName) {
       Preconditions.checkArgument(
           Objects.equals(logViewName.pathTemplate, PROJECT_LOCATION_BUCKET_VIEW),
           "toBuilder is only supported when LogViewName has the pattern of projects/{project}/locations/{location}/buckets/{bucket}/views/{view}");
-      project = logViewName.project;
-      location = logViewName.location;
-      bucket = logViewName.bucket;
-      view = logViewName.view;
+      this.project = logViewName.project;
+      this.location = logViewName.location;
+      this.bucket = logViewName.bucket;
+      this.view = logViewName.view;
     }
 
     public LogViewName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/OrganizationLocationName.java b/test/integration/goldens/logging/com/google/logging/v2/OrganizationLocationName.java
index 6f358bef84..316fdec7e9 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/OrganizationLocationName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/OrganizationLocationName.java
@@ -181,8 +181,8 @@ public Builder setLocation(String location) {
     }
 
     private Builder(OrganizationLocationName organizationLocationName) {
-      organization = organizationLocationName.organization;
-      location = organizationLocationName.location;
+      this.organization = organizationLocationName.organization;
+      this.location = organizationLocationName.location;
     }
 
     public OrganizationLocationName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/OrganizationName.java b/test/integration/goldens/logging/com/google/logging/v2/OrganizationName.java
index a4bb999c2e..b04b9c43d6 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/OrganizationName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/OrganizationName.java
@@ -158,7 +158,7 @@ public Builder setOrganization(String organization) {
     }
 
     private Builder(OrganizationName organizationName) {
-      organization = organizationName.organization;
+      this.organization = organizationName.organization;
     }
 
     public OrganizationName build() {
diff --git a/test/integration/goldens/logging/com/google/logging/v2/ProjectName.java b/test/integration/goldens/logging/com/google/logging/v2/ProjectName.java
index 2e4f451909..4975232f60 100644
--- a/test/integration/goldens/logging/com/google/logging/v2/ProjectName.java
+++ b/test/integration/goldens/logging/com/google/logging/v2/ProjectName.java
@@ -158,7 +158,7 @@ public Builder setProject(String project) {
     }
 
     private Builder(ProjectName projectName) {
-      project = projectName.project;
+      this.project = projectName.project;
     }
 
     public ProjectName build() {
diff --git a/test/integration/goldens/pubsub/BUILD.bazel b/test/integration/goldens/pubsub/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/pubsub/BUILD.bazel
+++ b/test/integration/goldens/pubsub/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/MockIAMPolicyImpl.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/MockIAMPolicyImpl.java
index 836144b7ee..e4528ae534 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/MockIAMPolicyImpl.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/MockIAMPolicyImpl.java
@@ -64,11 +64,13 @@ public void reset() {
   }
 
   @Override
-  public void setIamPolicy(SetIamPolicyRequest request, StreamObserver<Policy> responseObserver) {
+  public void testIamPermissions(
+      TestIamPermissionsRequest request,
+      StreamObserver<TestIamPermissionsResponse> responseObserver) {
     Object response = responses.poll();
-    if (response instanceof Policy) {
+    if (response instanceof TestIamPermissionsResponse) {
       requests.add(request);
-      responseObserver.onNext(((Policy) response));
+      responseObserver.onNext(((TestIamPermissionsResponse) response));
       responseObserver.onCompleted();
     } else if (response instanceof Exception) {
       responseObserver.onError(((Exception) response));
@@ -76,15 +78,15 @@ public void setIamPolicy(SetIamPolicyRequest request, StreamObserver<Policy> res
       responseObserver.onError(
           new IllegalArgumentException(
               String.format(
-                  "Unrecognized response type %s for method SetIamPolicy, expected %s or %s",
+                  "Unrecognized response type %s for method TestIamPermissions, expected %s or %s",
                   response == null ? "null" : response.getClass().getName(),
-                  Policy.class.getName(),
+                  TestIamPermissionsResponse.class.getName(),
                   Exception.class.getName())));
     }
   }
 
   @Override
-  public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> responseObserver) {
+  public void setIamPolicy(SetIamPolicyRequest request, StreamObserver<Policy> responseObserver) {
     Object response = responses.poll();
     if (response instanceof Policy) {
       requests.add(request);
@@ -96,7 +98,7 @@ public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> res
       responseObserver.onError(
           new IllegalArgumentException(
               String.format(
-                  "Unrecognized response type %s for method GetIamPolicy, expected %s or %s",
+                  "Unrecognized response type %s for method SetIamPolicy, expected %s or %s",
                   response == null ? "null" : response.getClass().getName(),
                   Policy.class.getName(),
                   Exception.class.getName())));
@@ -104,13 +106,11 @@ public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> res
   }
 
   @Override
-  public void testIamPermissions(
-      TestIamPermissionsRequest request,
-      StreamObserver<TestIamPermissionsResponse> responseObserver) {
+  public void getIamPolicy(GetIamPolicyRequest request, StreamObserver<Policy> responseObserver) {
     Object response = responses.poll();
-    if (response instanceof TestIamPermissionsResponse) {
+    if (response instanceof Policy) {
       requests.add(request);
-      responseObserver.onNext(((TestIamPermissionsResponse) response));
+      responseObserver.onNext(((Policy) response));
       responseObserver.onCompleted();
     } else if (response instanceof Exception) {
       responseObserver.onError(((Exception) response));
@@ -118,9 +118,9 @@ public void testIamPermissions(
       responseObserver.onError(
           new IllegalArgumentException(
               String.format(
-                  "Unrecognized response type %s for method TestIamPermissions, expected %s or %s",
+                  "Unrecognized response type %s for method GetIamPolicy, expected %s or %s",
                   response == null ? "null" : response.getClass().getName(),
-                  TestIamPermissionsResponse.class.getName(),
+                  Policy.class.getName(),
                   Exception.class.getName())));
     }
   }
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClient.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClient.java
index 13acfd990c..fa217f1637 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClient.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.pubsub.v1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -31,7 +30,6 @@
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.Policy;
-import com.google.iam.v1.ProjectName;
 import com.google.iam.v1.SetIamPolicyRequest;
 import com.google.iam.v1.TestIamPermissionsRequest;
 import com.google.iam.v1.TestIamPermissionsResponse;
@@ -41,6 +39,7 @@
 import com.google.pubsub.v1.GetSchemaRequest;
 import com.google.pubsub.v1.ListSchemasRequest;
 import com.google.pubsub.v1.ListSchemasResponse;
+import com.google.pubsub.v1.ProjectName;
 import com.google.pubsub.v1.Schema;
 import com.google.pubsub.v1.SchemaName;
 import com.google.pubsub.v1.ValidateMessageRequest;
@@ -54,8 +53,10 @@
 
 // AUTO-GENERATED DOCUMENTATION AND CLASS.
 /**
- * This class provides the ability to make remote calls to the backing service through method calls
- * that map to API methods. Sample code to get started:
+ * Service Description: Service for doing schema-related operations.
+ *
+ * <p>This class provides the ability to make remote calls to the backing service through method
+ * calls that map to API methods. Sample code to get started:
  *
  * <pre>{@code
  * try (SchemaServiceClient schemaServiceClient = SchemaServiceClient.create()) {
@@ -965,14 +966,7 @@ public static ApiFuture<ListSchemasPagedResponse> createAsync(
       ApiFuture<ListSchemasPage> futurePage =
           ListSchemasPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListSchemasPage, ListSchemasPagedResponse>() {
-            @Override
-            public ListSchemasPagedResponse apply(ListSchemasPage input) {
-              return new ListSchemasPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListSchemasPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListSchemasPagedResponse(ListSchemasPage page) {
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClientTest.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClientTest.java
index 9a2ce5e16b..ace5e7d42b 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClientTest.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceClientTest.java
@@ -30,7 +30,6 @@
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.GetPolicyOptions;
 import com.google.iam.v1.Policy;
-import com.google.iam.v1.ProjectName;
 import com.google.iam.v1.SetIamPolicyRequest;
 import com.google.iam.v1.TestIamPermissionsRequest;
 import com.google.iam.v1.TestIamPermissionsResponse;
@@ -43,6 +42,7 @@
 import com.google.pubsub.v1.GetSchemaRequest;
 import com.google.pubsub.v1.ListSchemasRequest;
 import com.google.pubsub.v1.ListSchemasResponse;
+import com.google.pubsub.v1.ProjectName;
 import com.google.pubsub.v1.Schema;
 import com.google.pubsub.v1.SchemaName;
 import com.google.pubsub.v1.ValidateMessageRequest;
@@ -65,11 +65,11 @@
 
 @Generated("by gapic-generator-java")
 public class SchemaServiceClientTest {
-  private static MockServiceHelper mockServiceHelper;
-  private static MockSchemaService mockSchemaService;
-  private SchemaServiceClient client;
   private static MockIAMPolicy mockIAMPolicy;
+  private static MockSchemaService mockSchemaService;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private SchemaServiceClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceSettings.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceSettings.java
index da29b9f2de..4f7dfdda43 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceSettings.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SchemaServiceSettings.java
@@ -218,14 +218,13 @@ public SchemaServiceStubSettings.Builder getStubSettingsBuilder() {
       return ((SchemaServiceStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClient.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClient.java
index c7d77041cb..a6adbe6945 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClient.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.pubsub.v1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -32,7 +31,6 @@
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.Policy;
-import com.google.iam.v1.ProjectName;
 import com.google.iam.v1.SetIamPolicyRequest;
 import com.google.iam.v1.TestIamPermissionsRequest;
 import com.google.iam.v1.TestIamPermissionsResponse;
@@ -49,6 +47,7 @@
 import com.google.pubsub.v1.ListSubscriptionsResponse;
 import com.google.pubsub.v1.ModifyAckDeadlineRequest;
 import com.google.pubsub.v1.ModifyPushConfigRequest;
+import com.google.pubsub.v1.ProjectName;
 import com.google.pubsub.v1.PullRequest;
 import com.google.pubsub.v1.PullResponse;
 import com.google.pubsub.v1.PushConfig;
@@ -1190,6 +1189,63 @@ public final UnaryCallable<AcknowledgeRequest, Empty> acknowledgeCallable() {
     return stub.acknowledgeCallable();
   }
 
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Pulls messages from the server. The server may return `UNAVAILABLE` if there are too many
+   * concurrent pull requests pending for the given subscription.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (SubscriptionAdminClient subscriptionAdminClient = SubscriptionAdminClient.create()) {
+   *   SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
+   *   int maxMessages = 496131527;
+   *   PullResponse response = subscriptionAdminClient.pull(subscription, maxMessages);
+   * }
+   * }</pre>
+   *
+   * @param subscription Required. The subscription from which messages should be pulled. Format is
+   *     `projects/{project}/subscriptions/{sub}`.
+   * @param maxMessages Required. The maximum number of messages to return for this request. Must be
+   *     a positive integer. The Pub/Sub system may return fewer than the number specified.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final PullResponse pull(SubscriptionName subscription, int maxMessages) {
+    PullRequest request =
+        PullRequest.newBuilder()
+            .setSubscription(subscription == null ? null : subscription.toString())
+            .setMaxMessages(maxMessages)
+            .build();
+    return pull(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Pulls messages from the server. The server may return `UNAVAILABLE` if there are too many
+   * concurrent pull requests pending for the given subscription.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (SubscriptionAdminClient subscriptionAdminClient = SubscriptionAdminClient.create()) {
+   *   String subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]").toString();
+   *   int maxMessages = 496131527;
+   *   PullResponse response = subscriptionAdminClient.pull(subscription, maxMessages);
+   * }
+   * }</pre>
+   *
+   * @param subscription Required. The subscription from which messages should be pulled. Format is
+   *     `projects/{project}/subscriptions/{sub}`.
+   * @param maxMessages Required. The maximum number of messages to return for this request. Must be
+   *     a positive integer. The Pub/Sub system may return fewer than the number specified.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final PullResponse pull(String subscription, int maxMessages) {
+    PullRequest request =
+        PullRequest.newBuilder().setSubscription(subscription).setMaxMessages(maxMessages).build();
+    return pull(request);
+  }
+
   // AUTO-GENERATED DOCUMENTATION AND METHOD.
   /**
    * Pulls messages from the server. The server may return `UNAVAILABLE` if there are too many
@@ -2440,12 +2496,7 @@ public static ApiFuture<ListSubscriptionsPagedResponse> createAsync(
           ListSubscriptionsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListSubscriptionsPage, ListSubscriptionsPagedResponse>() {
-            @Override
-            public ListSubscriptionsPagedResponse apply(ListSubscriptionsPage input) {
-              return new ListSubscriptionsPagedResponse(input);
-            }
-          },
+          input -> new ListSubscriptionsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -2525,12 +2576,7 @@ public static ApiFuture<ListSnapshotsPagedResponse> createAsync(
           ListSnapshotsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListSnapshotsPage, ListSnapshotsPagedResponse>() {
-            @Override
-            public ListSnapshotsPagedResponse apply(ListSnapshotsPage input) {
-              return new ListSnapshotsPagedResponse(input);
-            }
-          },
+          input -> new ListSnapshotsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClientTest.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClientTest.java
index 2686f5316f..dd1bd27dac 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClientTest.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminClientTest.java
@@ -35,7 +35,6 @@
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.GetPolicyOptions;
 import com.google.iam.v1.Policy;
-import com.google.iam.v1.ProjectName;
 import com.google.iam.v1.SetIamPolicyRequest;
 import com.google.iam.v1.TestIamPermissionsRequest;
 import com.google.iam.v1.TestIamPermissionsResponse;
@@ -59,6 +58,7 @@
 import com.google.pubsub.v1.ListSubscriptionsResponse;
 import com.google.pubsub.v1.ModifyAckDeadlineRequest;
 import com.google.pubsub.v1.ModifyPushConfigRequest;
+import com.google.pubsub.v1.ProjectName;
 import com.google.pubsub.v1.PullRequest;
 import com.google.pubsub.v1.PullResponse;
 import com.google.pubsub.v1.PushConfig;
@@ -93,11 +93,11 @@
 
 @Generated("by gapic-generator-java")
 public class SubscriptionAdminClientTest {
+  private static MockIAMPolicy mockIAMPolicy;
   private static MockServiceHelper mockServiceHelper;
   private static MockSubscriber mockSubscriber;
-  private SubscriptionAdminClient client;
-  private static MockIAMPolicy mockIAMPolicy;
   private LocalChannelProvider channelProvider;
+  private SubscriptionAdminClient client;
 
   @BeforeClass
   public static void startStaticServer() {
@@ -847,6 +847,84 @@ public void pullTest() throws Exception {
         PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
     mockSubscriber.addResponse(expectedResponse);
 
+    SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
+    int maxMessages = 496131527;
+
+    PullResponse actualResponse = client.pull(subscription, maxMessages);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockSubscriber.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    PullRequest actualRequest = ((PullRequest) actualRequests.get(0));
+
+    Assert.assertEquals(subscription.toString(), actualRequest.getSubscription());
+    Assert.assertEquals(maxMessages, actualRequest.getMaxMessages());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void pullExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockSubscriber.addException(exception);
+
+    try {
+      SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
+      int maxMessages = 496131527;
+      client.pull(subscription, maxMessages);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void pullTest2() throws Exception {
+    PullResponse expectedResponse =
+        PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
+    mockSubscriber.addResponse(expectedResponse);
+
+    String subscription = "subscription341203229";
+    int maxMessages = 496131527;
+
+    PullResponse actualResponse = client.pull(subscription, maxMessages);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockSubscriber.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    PullRequest actualRequest = ((PullRequest) actualRequests.get(0));
+
+    Assert.assertEquals(subscription, actualRequest.getSubscription());
+    Assert.assertEquals(maxMessages, actualRequest.getMaxMessages());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void pullExceptionTest2() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockSubscriber.addException(exception);
+
+    try {
+      String subscription = "subscription341203229";
+      int maxMessages = 496131527;
+      client.pull(subscription, maxMessages);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void pullTest3() throws Exception {
+    PullResponse expectedResponse =
+        PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
+    mockSubscriber.addResponse(expectedResponse);
+
     SubscriptionName subscription = SubscriptionName.of("[PROJECT]", "[SUBSCRIPTION]");
     boolean returnImmediately = true;
     int maxMessages = 496131527;
@@ -868,7 +946,7 @@ public void pullTest() throws Exception {
   }
 
   @Test
-  public void pullExceptionTest() throws Exception {
+  public void pullExceptionTest3() throws Exception {
     StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
     mockSubscriber.addException(exception);
 
@@ -884,7 +962,7 @@ public void pullExceptionTest() throws Exception {
   }
 
   @Test
-  public void pullTest2() throws Exception {
+  public void pullTest4() throws Exception {
     PullResponse expectedResponse =
         PullResponse.newBuilder().addAllReceivedMessages(new ArrayList<ReceivedMessage>()).build();
     mockSubscriber.addResponse(expectedResponse);
@@ -910,7 +988,7 @@ public void pullTest2() throws Exception {
   }
 
   @Test
-  public void pullExceptionTest2() throws Exception {
+  public void pullExceptionTest4() throws Exception {
     StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
     mockSubscriber.addException(exception);
 
@@ -930,6 +1008,8 @@ public void streamingPullTest() throws Exception {
     StreamingPullResponse expectedResponse =
         StreamingPullResponse.newBuilder()
             .addAllReceivedMessages(new ArrayList<ReceivedMessage>())
+            .setSubscriptionProperties(
+                StreamingPullResponse.SubscriptionProperties.newBuilder().build())
             .build();
     mockSubscriber.addResponse(expectedResponse);
     StreamingPullRequest request =
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminSettings.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminSettings.java
index e41dc3b133..d9680d778a 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminSettings.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/SubscriptionAdminSettings.java
@@ -285,14 +285,13 @@ public SubscriberStubSettings.Builder getStubSettingsBuilder() {
       return ((SubscriberStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClient.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClient.java
index 21cafd6f67..802fe3e940 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClient.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.pubsub.v1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -31,7 +30,6 @@
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.Policy;
-import com.google.iam.v1.ProjectName;
 import com.google.iam.v1.SetIamPolicyRequest;
 import com.google.iam.v1.TestIamPermissionsRequest;
 import com.google.iam.v1.TestIamPermissionsResponse;
@@ -46,6 +44,7 @@
 import com.google.pubsub.v1.ListTopicSubscriptionsResponse;
 import com.google.pubsub.v1.ListTopicsRequest;
 import com.google.pubsub.v1.ListTopicsResponse;
+import com.google.pubsub.v1.ProjectName;
 import com.google.pubsub.v1.PublishRequest;
 import com.google.pubsub.v1.PublishResponse;
 import com.google.pubsub.v1.PubsubMessage;
@@ -1309,14 +1308,7 @@ public static ApiFuture<ListTopicsPagedResponse> createAsync(
       ApiFuture<ListTopicsPage> futurePage =
           ListTopicsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
-          futurePage,
-          new ApiFunction<ListTopicsPage, ListTopicsPagedResponse>() {
-            @Override
-            public ListTopicsPagedResponse apply(ListTopicsPage input) {
-              return new ListTopicsPagedResponse(input);
-            }
-          },
-          MoreExecutors.directExecutor());
+          futurePage, input -> new ListTopicsPagedResponse(input), MoreExecutors.directExecutor());
     }
 
     private ListTopicsPagedResponse(ListTopicsPage page) {
@@ -1390,12 +1382,7 @@ public static ApiFuture<ListTopicSubscriptionsPagedResponse> createAsync(
           ListTopicSubscriptionsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListTopicSubscriptionsPage, ListTopicSubscriptionsPagedResponse>() {
-            @Override
-            public ListTopicSubscriptionsPagedResponse apply(ListTopicSubscriptionsPage input) {
-              return new ListTopicSubscriptionsPagedResponse(input);
-            }
-          },
+          input -> new ListTopicSubscriptionsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
@@ -1475,12 +1462,7 @@ public static ApiFuture<ListTopicSnapshotsPagedResponse> createAsync(
           ListTopicSnapshotsPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListTopicSnapshotsPage, ListTopicSnapshotsPagedResponse>() {
-            @Override
-            public ListTopicSnapshotsPagedResponse apply(ListTopicSnapshotsPage input) {
-              return new ListTopicSnapshotsPagedResponse(input);
-            }
-          },
+          input -> new ListTopicSnapshotsPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClientTest.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClientTest.java
index 94b7162fba..09b8de0f90 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClientTest.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminClientTest.java
@@ -32,7 +32,6 @@
 import com.google.iam.v1.GetIamPolicyRequest;
 import com.google.iam.v1.GetPolicyOptions;
 import com.google.iam.v1.Policy;
-import com.google.iam.v1.ProjectName;
 import com.google.iam.v1.SetIamPolicyRequest;
 import com.google.iam.v1.TestIamPermissionsRequest;
 import com.google.iam.v1.TestIamPermissionsResponse;
@@ -51,6 +50,7 @@
 import com.google.pubsub.v1.ListTopicsRequest;
 import com.google.pubsub.v1.ListTopicsResponse;
 import com.google.pubsub.v1.MessageStoragePolicy;
+import com.google.pubsub.v1.ProjectName;
 import com.google.pubsub.v1.PublishRequest;
 import com.google.pubsub.v1.PublishResponse;
 import com.google.pubsub.v1.PubsubMessage;
@@ -76,11 +76,11 @@
 
 @Generated("by gapic-generator-java")
 public class TopicAdminClientTest {
-  private static MockServiceHelper mockServiceHelper;
-  private static MockPublisher mockPublisher;
-  private TopicAdminClient client;
   private static MockIAMPolicy mockIAMPolicy;
+  private static MockPublisher mockPublisher;
+  private static MockServiceHelper mockServiceHelper;
   private LocalChannelProvider channelProvider;
+  private TopicAdminClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminSettings.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminSettings.java
index a402b3333d..e17e7237eb 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminSettings.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/TopicAdminSettings.java
@@ -245,14 +245,13 @@ public PublisherStubSettings.Builder getStubSettingsBuilder() {
       return ((PublisherStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/gapic_metadata.json b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/gapic_metadata.json
index ec835fc74c..8efac12d01 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/gapic_metadata.json
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/gapic_metadata.json
@@ -92,7 +92,7 @@
               "methods": ["modifyPushConfig", "modifyPushConfig", "modifyPushConfig", "modifyPushConfigCallable"]
             },
             "Pull": {
-              "methods": ["pull", "pull", "pull", "pullCallable"]
+              "methods": ["pull", "pull", "pull", "pull", "pull", "pullCallable"]
             },
             "Seek": {
               "methods": ["seek", "seekCallable"]
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/package-info.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/package-info.java
index 776d93208b..128d542475 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/package-info.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/package-info.java
@@ -54,6 +54,8 @@
  *
  * <p>======================= SchemaServiceClient =======================
  *
+ * <p>Service Description: Service for doing schema-related operations.
+ *
  * <p>Sample for SchemaServiceClient:
  *
  * <pre>{@code
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcPublisherStub.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcPublisherStub.java
index 2b5ce28a06..3b4330559f 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcPublisherStub.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcPublisherStub.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.iam.v1.GetIamPolicyRequest;
@@ -242,65 +241,50 @@ protected GrpcPublisherStub(
         GrpcCallSettings.<Topic, Topic>newBuilder()
             .setMethodDescriptor(createTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<Topic>() {
-                  @Override
-                  public Map<String, String> extract(Topic request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateTopicRequest, Topic> updateTopicTransportSettings =
         GrpcCallSettings.<UpdateTopicRequest, Topic>newBuilder()
             .setMethodDescriptor(updateTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateTopicRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateTopicRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic.name", String.valueOf(request.getTopic().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic.name", String.valueOf(request.getTopic().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<PublishRequest, PublishResponse> publishTransportSettings =
         GrpcCallSettings.<PublishRequest, PublishResponse>newBuilder()
             .setMethodDescriptor(publishMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<PublishRequest>() {
-                  @Override
-                  public Map<String, String> extract(PublishRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic", String.valueOf(request.getTopic()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic", String.valueOf(request.getTopic()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetTopicRequest, Topic> getTopicTransportSettings =
         GrpcCallSettings.<GetTopicRequest, Topic>newBuilder()
             .setMethodDescriptor(getTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetTopicRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetTopicRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic", String.valueOf(request.getTopic()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic", String.valueOf(request.getTopic()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListTopicsRequest, ListTopicsResponse> listTopicsTransportSettings =
         GrpcCallSettings.<ListTopicsRequest, ListTopicsResponse>newBuilder()
             .setMethodDescriptor(listTopicsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListTopicsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListTopicsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("project", String.valueOf(request.getProject()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("project", String.valueOf(request.getProject()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListTopicSubscriptionsRequest, ListTopicSubscriptionsResponse>
@@ -309,13 +293,10 @@ public Map<String, String> extract(ListTopicsRequest request) {
                 .<ListTopicSubscriptionsRequest, ListTopicSubscriptionsResponse>newBuilder()
                 .setMethodDescriptor(listTopicSubscriptionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListTopicSubscriptionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListTopicSubscriptionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("topic", String.valueOf(request.getTopic()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("topic", String.valueOf(request.getTopic()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ListTopicSnapshotsRequest, ListTopicSnapshotsResponse>
@@ -323,26 +304,20 @@ public Map<String, String> extract(ListTopicSubscriptionsRequest request) {
             GrpcCallSettings.<ListTopicSnapshotsRequest, ListTopicSnapshotsResponse>newBuilder()
                 .setMethodDescriptor(listTopicSnapshotsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListTopicSnapshotsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListTopicSnapshotsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("topic", String.valueOf(request.getTopic()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("topic", String.valueOf(request.getTopic()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<DeleteTopicRequest, Empty> deleteTopicTransportSettings =
         GrpcCallSettings.<DeleteTopicRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteTopicMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteTopicRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteTopicRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("topic", String.valueOf(request.getTopic()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("topic", String.valueOf(request.getTopic()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DetachSubscriptionRequest, DetachSubscriptionResponse>
@@ -350,39 +325,30 @@ public Map<String, String> extract(DeleteTopicRequest request) {
             GrpcCallSettings.<DetachSubscriptionRequest, DetachSubscriptionResponse>newBuilder()
                 .setMethodDescriptor(detachSubscriptionMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<DetachSubscriptionRequest>() {
-                      @Override
-                      public Map<String, String> extract(DetachSubscriptionRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("subscription", String.valueOf(request.getSubscription()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("subscription", String.valueOf(request.getSubscription()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<SetIamPolicyRequest, Policy> setIamPolicyTransportSettings =
         GrpcCallSettings.<SetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(setIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(SetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetIamPolicyRequest, Policy> getIamPolicyTransportSettings =
         GrpcCallSettings.<GetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(getIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<TestIamPermissionsRequest, TestIamPermissionsResponse>
@@ -390,13 +356,10 @@ public Map<String, String> extract(GetIamPolicyRequest request) {
             GrpcCallSettings.<TestIamPermissionsRequest, TestIamPermissionsResponse>newBuilder()
                 .setMethodDescriptor(testIamPermissionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<TestIamPermissionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(TestIamPermissionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("resource", String.valueOf(request.getResource()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("resource", String.valueOf(request.getResource()));
+                      return params.build();
                     })
                 .build();
 
@@ -549,7 +512,13 @@ public UnaryCallable<GetIamPolicyRequest, Policy> getIamPolicyCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSchemaServiceStub.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSchemaServiceStub.java
index 11bac90c7d..2ec4a27314 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSchemaServiceStub.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSchemaServiceStub.java
@@ -23,7 +23,6 @@
 import com.google.api.gax.grpc.GrpcCallSettings;
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.iam.v1.GetIamPolicyRequest;
@@ -201,52 +200,40 @@ protected GrpcSchemaServiceStub(
         GrpcCallSettings.<CreateSchemaRequest, Schema>newBuilder()
             .setMethodDescriptor(createSchemaMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateSchemaRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateSchemaRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetSchemaRequest, Schema> getSchemaTransportSettings =
         GrpcCallSettings.<GetSchemaRequest, Schema>newBuilder()
             .setMethodDescriptor(getSchemaMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetSchemaRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetSchemaRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListSchemasRequest, ListSchemasResponse> listSchemasTransportSettings =
         GrpcCallSettings.<ListSchemasRequest, ListSchemasResponse>newBuilder()
             .setMethodDescriptor(listSchemasMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListSchemasRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListSchemasRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteSchemaRequest, Empty> deleteSchemaTransportSettings =
         GrpcCallSettings.<DeleteSchemaRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteSchemaMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteSchemaRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteSchemaRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ValidateSchemaRequest, ValidateSchemaResponse>
@@ -254,13 +241,10 @@ public Map<String, String> extract(DeleteSchemaRequest request) {
             GrpcCallSettings.<ValidateSchemaRequest, ValidateSchemaResponse>newBuilder()
                 .setMethodDescriptor(validateSchemaMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ValidateSchemaRequest>() {
-                      @Override
-                      public Map<String, String> extract(ValidateSchemaRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<ValidateMessageRequest, ValidateMessageResponse>
@@ -268,39 +252,30 @@ public Map<String, String> extract(ValidateSchemaRequest request) {
             GrpcCallSettings.<ValidateMessageRequest, ValidateMessageResponse>newBuilder()
                 .setMethodDescriptor(validateMessageMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ValidateMessageRequest>() {
-                      @Override
-                      public Map<String, String> extract(ValidateMessageRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("parent", String.valueOf(request.getParent()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("parent", String.valueOf(request.getParent()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<SetIamPolicyRequest, Policy> setIamPolicyTransportSettings =
         GrpcCallSettings.<SetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(setIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(SetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetIamPolicyRequest, Policy> getIamPolicyTransportSettings =
         GrpcCallSettings.<GetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(getIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<TestIamPermissionsRequest, TestIamPermissionsResponse>
@@ -308,13 +283,10 @@ public Map<String, String> extract(GetIamPolicyRequest request) {
             GrpcCallSettings.<TestIamPermissionsRequest, TestIamPermissionsResponse>newBuilder()
                 .setMethodDescriptor(testIamPermissionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<TestIamPermissionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(TestIamPermissionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("resource", String.valueOf(request.getResource()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("resource", String.valueOf(request.getResource()));
+                      return params.build();
                     })
                 .build();
 
@@ -412,7 +384,13 @@ public UnaryCallable<GetIamPolicyRequest, Policy> getIamPolicyCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSubscriberStub.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSubscriberStub.java
index 8580e626f8..f4da747061 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSubscriberStub.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/GrpcSubscriberStub.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.BidiStreamingCallable;
 import com.google.api.gax.rpc.ClientContext;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.common.collect.ImmutableMap;
 import com.google.iam.v1.GetIamPolicyRequest;
@@ -326,40 +325,31 @@ protected GrpcSubscriberStub(
         GrpcCallSettings.<Subscription, Subscription>newBuilder()
             .setMethodDescriptor(createSubscriptionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<Subscription>() {
-                  @Override
-                  public Map<String, String> extract(Subscription request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetSubscriptionRequest, Subscription> getSubscriptionTransportSettings =
         GrpcCallSettings.<GetSubscriptionRequest, Subscription>newBuilder()
             .setMethodDescriptor(getSubscriptionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetSubscriptionRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetSubscriptionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateSubscriptionRequest, Subscription> updateSubscriptionTransportSettings =
         GrpcCallSettings.<UpdateSubscriptionRequest, Subscription>newBuilder()
             .setMethodDescriptor(updateSubscriptionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateSubscriptionRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateSubscriptionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put(
-                        "subscription.name", String.valueOf(request.getSubscription().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put(
+                      "subscription.name", String.valueOf(request.getSubscription().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListSubscriptionsRequest, ListSubscriptionsResponse>
@@ -367,65 +357,50 @@ public Map<String, String> extract(UpdateSubscriptionRequest request) {
             GrpcCallSettings.<ListSubscriptionsRequest, ListSubscriptionsResponse>newBuilder()
                 .setMethodDescriptor(listSubscriptionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<ListSubscriptionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(ListSubscriptionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("project", String.valueOf(request.getProject()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("project", String.valueOf(request.getProject()));
+                      return params.build();
                     })
                 .build();
     GrpcCallSettings<DeleteSubscriptionRequest, Empty> deleteSubscriptionTransportSettings =
         GrpcCallSettings.<DeleteSubscriptionRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteSubscriptionMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteSubscriptionRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteSubscriptionRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ModifyAckDeadlineRequest, Empty> modifyAckDeadlineTransportSettings =
         GrpcCallSettings.<ModifyAckDeadlineRequest, Empty>newBuilder()
             .setMethodDescriptor(modifyAckDeadlineMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ModifyAckDeadlineRequest>() {
-                  @Override
-                  public Map<String, String> extract(ModifyAckDeadlineRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<AcknowledgeRequest, Empty> acknowledgeTransportSettings =
         GrpcCallSettings.<AcknowledgeRequest, Empty>newBuilder()
             .setMethodDescriptor(acknowledgeMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<AcknowledgeRequest>() {
-                  @Override
-                  public Map<String, String> extract(AcknowledgeRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<PullRequest, PullResponse> pullTransportSettings =
         GrpcCallSettings.<PullRequest, PullResponse>newBuilder()
             .setMethodDescriptor(pullMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<PullRequest>() {
-                  @Override
-                  public Map<String, String> extract(PullRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<StreamingPullRequest, StreamingPullResponse> streamingPullTransportSettings =
@@ -436,117 +411,90 @@ public Map<String, String> extract(PullRequest request) {
         GrpcCallSettings.<ModifyPushConfigRequest, Empty>newBuilder()
             .setMethodDescriptor(modifyPushConfigMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ModifyPushConfigRequest>() {
-                  @Override
-                  public Map<String, String> extract(ModifyPushConfigRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetSnapshotRequest, Snapshot> getSnapshotTransportSettings =
         GrpcCallSettings.<GetSnapshotRequest, Snapshot>newBuilder()
             .setMethodDescriptor(getSnapshotMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetSnapshotRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetSnapshotRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("snapshot", String.valueOf(request.getSnapshot()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("snapshot", String.valueOf(request.getSnapshot()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ListSnapshotsRequest, ListSnapshotsResponse> listSnapshotsTransportSettings =
         GrpcCallSettings.<ListSnapshotsRequest, ListSnapshotsResponse>newBuilder()
             .setMethodDescriptor(listSnapshotsMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListSnapshotsRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListSnapshotsRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("project", String.valueOf(request.getProject()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("project", String.valueOf(request.getProject()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateSnapshotRequest, Snapshot> createSnapshotTransportSettings =
         GrpcCallSettings.<CreateSnapshotRequest, Snapshot>newBuilder()
             .setMethodDescriptor(createSnapshotMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateSnapshotRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateSnapshotRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateSnapshotRequest, Snapshot> updateSnapshotTransportSettings =
         GrpcCallSettings.<UpdateSnapshotRequest, Snapshot>newBuilder()
             .setMethodDescriptor(updateSnapshotMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateSnapshotRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateSnapshotRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("snapshot.name", String.valueOf(request.getSnapshot().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("snapshot.name", String.valueOf(request.getSnapshot().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteSnapshotRequest, Empty> deleteSnapshotTransportSettings =
         GrpcCallSettings.<DeleteSnapshotRequest, Empty>newBuilder()
             .setMethodDescriptor(deleteSnapshotMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteSnapshotRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteSnapshotRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("snapshot", String.valueOf(request.getSnapshot()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("snapshot", String.valueOf(request.getSnapshot()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<SeekRequest, SeekResponse> seekTransportSettings =
         GrpcCallSettings.<SeekRequest, SeekResponse>newBuilder()
             .setMethodDescriptor(seekMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SeekRequest>() {
-                  @Override
-                  public Map<String, String> extract(SeekRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("subscription", String.valueOf(request.getSubscription()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("subscription", String.valueOf(request.getSubscription()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<SetIamPolicyRequest, Policy> setIamPolicyTransportSettings =
         GrpcCallSettings.<SetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(setIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<SetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(SetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetIamPolicyRequest, Policy> getIamPolicyTransportSettings =
         GrpcCallSettings.<GetIamPolicyRequest, Policy>newBuilder()
             .setMethodDescriptor(getIamPolicyMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetIamPolicyRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetIamPolicyRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("resource", String.valueOf(request.getResource()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("resource", String.valueOf(request.getResource()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<TestIamPermissionsRequest, TestIamPermissionsResponse>
@@ -554,13 +502,10 @@ public Map<String, String> extract(GetIamPolicyRequest request) {
             GrpcCallSettings.<TestIamPermissionsRequest, TestIamPermissionsResponse>newBuilder()
                 .setMethodDescriptor(testIamPermissionsMethodDescriptor)
                 .setParamsExtractor(
-                    new RequestParamsExtractor<TestIamPermissionsRequest>() {
-                      @Override
-                      public Map<String, String> extract(TestIamPermissionsRequest request) {
-                        ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                        params.put("resource", String.valueOf(request.getResource()));
-                        return params.build();
-                      }
+                    request -> {
+                      ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                      params.put("resource", String.valueOf(request.getResource()));
+                      return params.build();
                     })
                 .build();
 
@@ -762,7 +707,13 @@ public UnaryCallable<GetIamPolicyRequest, Policy> getIamPolicyCallable() {
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/PublisherStubSettings.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/PublisherStubSettings.java
index 5909b0850c..166775ec3c 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/PublisherStubSettings.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/PublisherStubSettings.java
@@ -478,6 +478,11 @@ public static String getDefaultEndpoint() {
     return "pubsub.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "pubsub.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -485,7 +490,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -711,6 +718,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -792,14 +801,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SchemaServiceStubSettings.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SchemaServiceStubSettings.java
index 6f8f9b182e..fb8a87653d 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SchemaServiceStubSettings.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SchemaServiceStubSettings.java
@@ -242,6 +242,11 @@ public static String getDefaultEndpoint() {
     return "pubsub.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "pubsub.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -249,7 +254,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -401,6 +408,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -454,14 +463,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SubscriberStubSettings.java b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SubscriberStubSettings.java
index 55101f5595..567da1624b 100644
--- a/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SubscriberStubSettings.java
+++ b/test/integration/goldens/pubsub/com/google/cloud/pubsub/v1/stub/SubscriberStubSettings.java
@@ -383,6 +383,11 @@ public static String getDefaultEndpoint() {
     return "pubsub.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "pubsub.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -390,7 +395,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -653,6 +660,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -751,14 +760,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/pubsub/com/google/iam/v1/ProjectName.java b/test/integration/goldens/pubsub/com/google/pubsub/v1/ProjectName.java
similarity index 98%
rename from test/integration/goldens/pubsub/com/google/iam/v1/ProjectName.java
rename to test/integration/goldens/pubsub/com/google/pubsub/v1/ProjectName.java
index 21108a2658..4050e3e1aa 100644
--- a/test/integration/goldens/pubsub/com/google/iam/v1/ProjectName.java
+++ b/test/integration/goldens/pubsub/com/google/pubsub/v1/ProjectName.java
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.google.iam.v1;
+package com.google.pubsub.v1;
 
 import com.google.api.pathtemplate.PathTemplate;
 import com.google.api.resourcenames.ResourceName;
@@ -158,7 +158,7 @@ public Builder setProject(String project) {
     }
 
     private Builder(ProjectName projectName) {
-      project = projectName.project;
+      this.project = projectName.project;
     }
 
     public ProjectName build() {
diff --git a/test/integration/goldens/pubsub/com/google/pubsub/v1/SchemaName.java b/test/integration/goldens/pubsub/com/google/pubsub/v1/SchemaName.java
index 275fce55e7..af7c5feab1 100644
--- a/test/integration/goldens/pubsub/com/google/pubsub/v1/SchemaName.java
+++ b/test/integration/goldens/pubsub/com/google/pubsub/v1/SchemaName.java
@@ -180,8 +180,8 @@ public Builder setSchema(String schema) {
     }
 
     private Builder(SchemaName schemaName) {
-      project = schemaName.project;
-      schema = schemaName.schema;
+      this.project = schemaName.project;
+      this.schema = schemaName.schema;
     }
 
     public SchemaName build() {
diff --git a/test/integration/goldens/pubsub/com/google/pubsub/v1/SnapshotName.java b/test/integration/goldens/pubsub/com/google/pubsub/v1/SnapshotName.java
index 67cb2458e2..fe26eefe0f 100644
--- a/test/integration/goldens/pubsub/com/google/pubsub/v1/SnapshotName.java
+++ b/test/integration/goldens/pubsub/com/google/pubsub/v1/SnapshotName.java
@@ -181,8 +181,8 @@ public Builder setSnapshot(String snapshot) {
     }
 
     private Builder(SnapshotName snapshotName) {
-      project = snapshotName.project;
-      snapshot = snapshotName.snapshot;
+      this.project = snapshotName.project;
+      this.snapshot = snapshotName.snapshot;
     }
 
     public SnapshotName build() {
diff --git a/test/integration/goldens/pubsub/com/google/pubsub/v1/SubscriptionName.java b/test/integration/goldens/pubsub/com/google/pubsub/v1/SubscriptionName.java
index 50131e8b35..0eed7889aa 100644
--- a/test/integration/goldens/pubsub/com/google/pubsub/v1/SubscriptionName.java
+++ b/test/integration/goldens/pubsub/com/google/pubsub/v1/SubscriptionName.java
@@ -181,8 +181,8 @@ public Builder setSubscription(String subscription) {
     }
 
     private Builder(SubscriptionName subscriptionName) {
-      project = subscriptionName.project;
-      subscription = subscriptionName.subscription;
+      this.project = subscriptionName.project;
+      this.subscription = subscriptionName.subscription;
     }
 
     public SubscriptionName build() {
diff --git a/test/integration/goldens/pubsub/com/google/pubsub/v1/TopicName.java b/test/integration/goldens/pubsub/com/google/pubsub/v1/TopicName.java
index 36d4289b67..dcb2fa83b1 100644
--- a/test/integration/goldens/pubsub/com/google/pubsub/v1/TopicName.java
+++ b/test/integration/goldens/pubsub/com/google/pubsub/v1/TopicName.java
@@ -224,8 +224,8 @@ private Builder(TopicName topicName) {
       Preconditions.checkArgument(
           Objects.equals(topicName.pathTemplate, PROJECT_TOPIC),
           "toBuilder is only supported when TopicName has the pattern of projects/{project}/topics/{topic}");
-      project = topicName.project;
-      topic = topicName.topic;
+      this.project = topicName.project;
+      this.topic = topicName.topic;
     }
 
     public TopicName build() {
diff --git a/test/integration/goldens/redis/BUILD.bazel b/test/integration/goldens/redis/BUILD.bazel
index 667772f01b..2822013159 100644
--- a/test/integration/goldens/redis/BUILD.bazel
+++ b/test/integration/goldens/redis/BUILD.bazel
@@ -2,8 +2,11 @@ package(default_visibility = ["//visibility:public"])
 
 filegroup(
     name = "goldens_files",
-    srcs = glob([
-        "*.java",
-        "gapic_metadata.json",
-    ]),
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
 )
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClient.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClient.java
index f62dcd329d..fe918026ed 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClient.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClient.java
@@ -16,7 +16,6 @@
 
 package com.google.cloud.redis.v1beta1;
 
-import com.google.api.core.ApiFunction;
 import com.google.api.core.ApiFuture;
 import com.google.api.core.ApiFutures;
 import com.google.api.core.BetaApi;
@@ -1463,12 +1462,7 @@ public static ApiFuture<ListInstancesPagedResponse> createAsync(
           ListInstancesPage.createEmptyPage().createPageAsync(context, futureResponse);
       return ApiFutures.transform(
           futurePage,
-          new ApiFunction<ListInstancesPage, ListInstancesPagedResponse>() {
-            @Override
-            public ListInstancesPagedResponse apply(ListInstancesPage input) {
-              return new ListInstancesPagedResponse(input);
-            }
-          },
+          input -> new ListInstancesPagedResponse(input),
           MoreExecutors.directExecutor());
     }
 
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java
index 41caaafeb1..63665485a3 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisClientTest.java
@@ -52,8 +52,8 @@
 public class CloudRedisClientTest {
   private static MockCloudRedis mockCloudRedis;
   private static MockServiceHelper mockServiceHelper;
-  private CloudRedisClient client;
   private LocalChannelProvider channelProvider;
+  private CloudRedisClient client;
 
   @BeforeClass
   public static void startStaticServer() {
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisSettings.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisSettings.java
index 250349fb1b..08436a1bd7 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisSettings.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/CloudRedisSettings.java
@@ -246,14 +246,13 @@ public CloudRedisStubSettings.Builder getStubSettingsBuilder() {
       return ((CloudRedisStubSettings.Builder) getStubSettings());
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(
           getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
       return this;
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/InstanceName.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/InstanceName.java
index b58cf0d5e9..c63c2c1f75 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/InstanceName.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/InstanceName.java
@@ -211,9 +211,9 @@ public Builder setInstance(String instance) {
     }
 
     private Builder(InstanceName instanceName) {
-      project = instanceName.project;
-      location = instanceName.location;
-      instance = instanceName.instance;
+      this.project = instanceName.project;
+      this.location = instanceName.location;
+      this.instance = instanceName.instance;
     }
 
     public InstanceName build() {
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/LocationName.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/LocationName.java
index ab2b214c7b..fdd464ceba 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/LocationName.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/LocationName.java
@@ -181,8 +181,8 @@ public Builder setLocation(String location) {
     }
 
     private Builder(LocationName locationName) {
-      project = locationName.project;
-      location = locationName.location;
+      this.project = locationName.project;
+      this.location = locationName.location;
     }
 
     public LocationName build() {
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java
index fcb157ea43..b92734fabc 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/CloudRedisStubSettings.java
@@ -294,6 +294,11 @@ public static String getDefaultEndpoint() {
     return "redis.googleapis.com:443";
   }
 
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "redis.mtls.googleapis.com:443";
+  }
+
   /** Returns the default service scopes. */
   public static List<String> getDefaultServiceScopes() {
     return DEFAULT_SERVICE_SCOPES;
@@ -301,7 +306,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */
@@ -499,6 +506,8 @@ private static Builder createDefault() {
       builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
       builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
       builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
 
       return initDefaults(builder);
     }
@@ -713,14 +722,13 @@ private static Builder initDefaults(Builder builder) {
       return builder;
     }
 
-    // NEXT_MAJOR_VER: remove 'throws Exception'.
     /**
      * Applies the given settings updater function to all of the unary API methods in this service.
      *
      * <p>Note: This method does not support applying settings to streaming methods.
      */
     public Builder applyToAllUnaryMethods(
-        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) throws Exception {
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
       super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
       return this;
     }
diff --git a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/GrpcCloudRedisStub.java b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/GrpcCloudRedisStub.java
index 24c34f9b6e..51347bcfd7 100644
--- a/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/GrpcCloudRedisStub.java
+++ b/test/integration/goldens/redis/com/google/cloud/redis/v1beta1/stub/GrpcCloudRedisStub.java
@@ -25,7 +25,6 @@
 import com.google.api.gax.grpc.GrpcStubCallableFactory;
 import com.google.api.gax.rpc.ClientContext;
 import com.google.api.gax.rpc.OperationCallable;
-import com.google.api.gax.rpc.RequestParamsExtractor;
 import com.google.api.gax.rpc.UnaryCallable;
 import com.google.cloud.redis.v1beta1.CreateInstanceRequest;
 import com.google.cloud.redis.v1beta1.DeleteInstanceRequest;
@@ -220,117 +219,90 @@ protected GrpcCloudRedisStub(
         GrpcCallSettings.<ListInstancesRequest, ListInstancesResponse>newBuilder()
             .setMethodDescriptor(listInstancesMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ListInstancesRequest>() {
-                  @Override
-                  public Map<String, String> extract(ListInstancesRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<GetInstanceRequest, Instance> getInstanceTransportSettings =
         GrpcCallSettings.<GetInstanceRequest, Instance>newBuilder()
             .setMethodDescriptor(getInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<GetInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(GetInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<CreateInstanceRequest, Operation> createInstanceTransportSettings =
         GrpcCallSettings.<CreateInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(createInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<CreateInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(CreateInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("parent", String.valueOf(request.getParent()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("parent", String.valueOf(request.getParent()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpdateInstanceRequest, Operation> updateInstanceTransportSettings =
         GrpcCallSettings.<UpdateInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(updateInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpdateInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpdateInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("instance.name", String.valueOf(request.getInstance().getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("instance.name", String.valueOf(request.getInstance().getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<UpgradeInstanceRequest, Operation> upgradeInstanceTransportSettings =
         GrpcCallSettings.<UpgradeInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(upgradeInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<UpgradeInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(UpgradeInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ImportInstanceRequest, Operation> importInstanceTransportSettings =
         GrpcCallSettings.<ImportInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(importInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ImportInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(ImportInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<ExportInstanceRequest, Operation> exportInstanceTransportSettings =
         GrpcCallSettings.<ExportInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(exportInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<ExportInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(ExportInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<FailoverInstanceRequest, Operation> failoverInstanceTransportSettings =
         GrpcCallSettings.<FailoverInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(failoverInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<FailoverInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(FailoverInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
     GrpcCallSettings<DeleteInstanceRequest, Operation> deleteInstanceTransportSettings =
         GrpcCallSettings.<DeleteInstanceRequest, Operation>newBuilder()
             .setMethodDescriptor(deleteInstanceMethodDescriptor)
             .setParamsExtractor(
-                new RequestParamsExtractor<DeleteInstanceRequest>() {
-                  @Override
-                  public Map<String, String> extract(DeleteInstanceRequest request) {
-                    ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
-                    params.put("name", String.valueOf(request.getName()));
-                    return params.build();
-                  }
+                request -> {
+                  ImmutableMap.Builder<String, String> params = ImmutableMap.builder();
+                  params.put("name", String.valueOf(request.getName()));
+                  return params.build();
                 })
             .build();
 
@@ -505,7 +477,13 @@ public OperationCallable<DeleteInstanceRequest, Empty, Any> deleteInstanceOperat
 
   @Override
   public final void close() {
-    shutdown();
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
   }
 
   @Override
diff --git a/test/integration/goldens/storage/BUILD.bazel b/test/integration/goldens/storage/BUILD.bazel
new file mode 100644
index 0000000000..2822013159
--- /dev/null
+++ b/test/integration/goldens/storage/BUILD.bazel
@@ -0,0 +1,12 @@
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "goldens_files",
+    srcs = glob(
+        ["**/*"],
+        exclude = [
+            "BUILD.bazel",
+            ".*.sw*",
+        ],
+    ),
+)
diff --git a/test/integration/goldens/storage/com/google/storage/v2/MockStorage.java b/test/integration/goldens/storage/com/google/storage/v2/MockStorage.java
new file mode 100644
index 0000000000..dbaae70d75
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/MockStorage.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.grpc.testing.MockGrpcService;
+import com.google.protobuf.AbstractMessage;
+import io.grpc.ServerServiceDefinition;
+import java.util.List;
+import javax.annotation.Generated;
+
+@BetaApi
+@Generated("by gapic-generator-java")
+public class MockStorage implements MockGrpcService {
+  private final MockStorageImpl serviceImpl;
+
+  public MockStorage() {
+    serviceImpl = new MockStorageImpl();
+  }
+
+  @Override
+  public List<AbstractMessage> getRequests() {
+    return serviceImpl.getRequests();
+  }
+
+  @Override
+  public void addResponse(AbstractMessage response) {
+    serviceImpl.addResponse(response);
+  }
+
+  @Override
+  public void addException(Exception exception) {
+    serviceImpl.addException(exception);
+  }
+
+  @Override
+  public ServerServiceDefinition getServiceDefinition() {
+    return serviceImpl.bindService();
+  }
+
+  @Override
+  public void reset() {
+    serviceImpl.reset();
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/MockStorageImpl.java b/test/integration/goldens/storage/com/google/storage/v2/MockStorageImpl.java
new file mode 100644
index 0000000000..a2787a85bd
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/MockStorageImpl.java
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2;
+
+import com.google.api.core.BetaApi;
+import com.google.protobuf.AbstractMessage;
+import com.google.storage.v2.StorageGrpc.StorageImplBase;
+import io.grpc.stub.StreamObserver;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+import javax.annotation.Generated;
+
+@BetaApi
+@Generated("by gapic-generator-java")
+public class MockStorageImpl extends StorageImplBase {
+  private List<AbstractMessage> requests;
+  private Queue<java.lang.Object> responses;
+
+  public MockStorageImpl() {
+    requests = new ArrayList<>();
+    responses = new LinkedList<>();
+  }
+
+  public List<AbstractMessage> getRequests() {
+    return requests;
+  }
+
+  public void addResponse(AbstractMessage response) {
+    responses.add(response);
+  }
+
+  public void setResponses(List<AbstractMessage> responses) {
+    this.responses = new LinkedList<java.lang.Object>(responses);
+  }
+
+  public void addException(Exception exception) {
+    responses.add(exception);
+  }
+
+  public void reset() {
+    requests = new ArrayList<>();
+    responses = new LinkedList<>();
+  }
+
+  @Override
+  public void readObject(
+      ReadObjectRequest request, StreamObserver<ReadObjectResponse> responseObserver) {
+    java.lang.Object response = responses.poll();
+    if (response instanceof ReadObjectResponse) {
+      requests.add(request);
+      responseObserver.onNext(((ReadObjectResponse) response));
+      responseObserver.onCompleted();
+    } else if (response instanceof Exception) {
+      responseObserver.onError(((Exception) response));
+    } else {
+      responseObserver.onError(
+          new IllegalArgumentException(
+              String.format(
+                  "Unrecognized response type %s for method ReadObject, expected %s or %s",
+                  response == null ? "null" : response.getClass().getName(),
+                  ReadObjectResponse.class.getName(),
+                  Exception.class.getName())));
+    }
+  }
+
+  @Override
+  public StreamObserver<WriteObjectRequest> writeObject(
+      final StreamObserver<WriteObjectResponse> responseObserver) {
+    StreamObserver<WriteObjectRequest> requestObserver =
+        new StreamObserver<WriteObjectRequest>() {
+          @Override
+          public void onNext(WriteObjectRequest value) {
+            requests.add(value);
+            final java.lang.Object response = responses.remove();
+            if (response instanceof WriteObjectResponse) {
+              responseObserver.onNext(((WriteObjectResponse) response));
+            } else if (response instanceof Exception) {
+              responseObserver.onError(((Exception) response));
+            } else {
+              responseObserver.onError(
+                  new IllegalArgumentException(
+                      String.format(
+                          "Unrecognized response type %s for method WriteObject, expected %s or %s",
+                          response == null ? "null" : response.getClass().getName(),
+                          WriteObjectResponse.class.getName(),
+                          Exception.class.getName())));
+            }
+          }
+
+          @Override
+          public void onError(Throwable t) {
+            responseObserver.onError(t);
+          }
+
+          @Override
+          public void onCompleted() {
+            responseObserver.onCompleted();
+          }
+        };
+    return requestObserver;
+  }
+
+  @Override
+  public void startResumableWrite(
+      StartResumableWriteRequest request,
+      StreamObserver<StartResumableWriteResponse> responseObserver) {
+    java.lang.Object response = responses.poll();
+    if (response instanceof StartResumableWriteResponse) {
+      requests.add(request);
+      responseObserver.onNext(((StartResumableWriteResponse) response));
+      responseObserver.onCompleted();
+    } else if (response instanceof Exception) {
+      responseObserver.onError(((Exception) response));
+    } else {
+      responseObserver.onError(
+          new IllegalArgumentException(
+              String.format(
+                  "Unrecognized response type %s for method StartResumableWrite, expected %s or %s",
+                  response == null ? "null" : response.getClass().getName(),
+                  StartResumableWriteResponse.class.getName(),
+                  Exception.class.getName())));
+    }
+  }
+
+  @Override
+  public void queryWriteStatus(
+      QueryWriteStatusRequest request, StreamObserver<QueryWriteStatusResponse> responseObserver) {
+    java.lang.Object response = responses.poll();
+    if (response instanceof QueryWriteStatusResponse) {
+      requests.add(request);
+      responseObserver.onNext(((QueryWriteStatusResponse) response));
+      responseObserver.onCompleted();
+    } else if (response instanceof Exception) {
+      responseObserver.onError(((Exception) response));
+    } else {
+      responseObserver.onError(
+          new IllegalArgumentException(
+              String.format(
+                  "Unrecognized response type %s for method QueryWriteStatus, expected %s or %s",
+                  response == null ? "null" : response.getClass().getName(),
+                  QueryWriteStatusResponse.class.getName(),
+                  Exception.class.getName())));
+    }
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/StorageClient.java b/test/integration/goldens/storage/com/google/storage/v2/StorageClient.java
new file mode 100644
index 0000000000..78b7fd7e08
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/StorageClient.java
@@ -0,0 +1,428 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2;
+
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.rpc.ClientStreamingCallable;
+import com.google.api.gax.rpc.ServerStreamingCallable;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.storage.v2.stub.StorageStub;
+import com.google.storage.v2.stub.StorageStubSettings;
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Service Description: Manages Google Cloud Storage resources.
+ *
+ * <p>This class provides the ability to make remote calls to the backing service through method
+ * calls that map to API methods. Sample code to get started:
+ *
+ * <pre>{@code
+ * try (StorageClient storageClient = StorageClient.create()) {
+ *   StartResumableWriteRequest request =
+ *       StartResumableWriteRequest.newBuilder()
+ *           .setWriteObjectSpec(WriteObjectSpec.newBuilder().build())
+ *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+ *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+ *           .build();
+ *   StartResumableWriteResponse response = storageClient.startResumableWrite(request);
+ * }
+ * }</pre>
+ *
+ * <p>Note: close() needs to be called on the StorageClient object to clean up resources such as
+ * threads. In the example above, try-with-resources is used, which automatically calls close().
+ *
+ * <p>The surface of this class includes several types of Java methods for each of the API's
+ * methods:
+ *
+ * <ol>
+ *   <li>A "flattened" method. With this type of method, the fields of the request type have been
+ *       converted into function parameters. It may be the case that not all fields are available as
+ *       parameters, and not every API method will have a flattened method entry point.
+ *   <li>A "request object" method. This type of method only takes one parameter, a request object,
+ *       which must be constructed before the call. Not every API method will have a request object
+ *       method.
+ *   <li>A "callable" method. This type of method takes no parameters and returns an immutable API
+ *       callable object, which can be used to initiate calls to the service.
+ * </ol>
+ *
+ * <p>See the individual methods for example code.
+ *
+ * <p>Many parameters require resource names to be formatted in a particular way. To assist with
+ * these names, this class includes a format method for each type of name, and additionally a parse
+ * method to extract the individual identifiers contained within names that are returned.
+ *
+ * <p>This class can be customized by passing in a custom instance of StorageSettings to create().
+ * For example:
+ *
+ * <p>To customize credentials:
+ *
+ * <pre>{@code
+ * StorageSettings storageSettings =
+ *     StorageSettings.newBuilder()
+ *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
+ *         .build();
+ * StorageClient storageClient = StorageClient.create(storageSettings);
+ * }</pre>
+ *
+ * <p>To customize the endpoint:
+ *
+ * <pre>{@code
+ * StorageSettings storageSettings = StorageSettings.newBuilder().setEndpoint(myEndpoint).build();
+ * StorageClient storageClient = StorageClient.create(storageSettings);
+ * }</pre>
+ *
+ * <p>Please refer to the GitHub repository's samples for more quickstart code snippets.
+ */
+@Generated("by gapic-generator-java")
+public class StorageClient implements BackgroundResource {
+  private final StorageSettings settings;
+  private final StorageStub stub;
+
+  /** Constructs an instance of StorageClient with default settings. */
+  public static final StorageClient create() throws IOException {
+    return create(StorageSettings.newBuilder().build());
+  }
+
+  /**
+   * Constructs an instance of StorageClient, using the given settings. The channels are created
+   * based on the settings passed in, or defaults for any settings that are not set.
+   */
+  public static final StorageClient create(StorageSettings settings) throws IOException {
+    return new StorageClient(settings);
+  }
+
+  /**
+   * Constructs an instance of StorageClient, using the given stub for making calls. This is for
+   * advanced usage - prefer using create(StorageSettings).
+   */
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public static final StorageClient create(StorageStub stub) {
+    return new StorageClient(stub);
+  }
+
+  /**
+   * Constructs an instance of StorageClient, using the given settings. This is protected so that it
+   * is easy to make a subclass, but otherwise, the static factory methods should be preferred.
+   */
+  protected StorageClient(StorageSettings settings) throws IOException {
+    this.settings = settings;
+    this.stub = ((StorageStubSettings) settings.getStubSettings()).createStub();
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  protected StorageClient(StorageStub stub) {
+    this.settings = null;
+    this.stub = stub;
+  }
+
+  public final StorageSettings getSettings() {
+    return settings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public StorageStub getStub() {
+    return stub;
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Reads an object's data.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   ReadObjectRequest request =
+   *       ReadObjectRequest.newBuilder()
+   *           .setBucket("bucket-1378203158")
+   *           .setObject("object-1023368385")
+   *           .setGeneration(305703192)
+   *           .setReadOffset(-715377828)
+   *           .setReadLimit(-164298798)
+   *           .setIfGenerationMatch(-1086241088)
+   *           .setIfGenerationNotMatch(1475720404)
+   *           .setIfMetagenerationMatch(1043427781)
+   *           .setIfMetagenerationNotMatch(1025430873)
+   *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+   *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+   *           .setReadMask(FieldMask.newBuilder().build())
+   *           .build();
+   *   ServerStream<ReadObjectResponse> stream = storageClient.readObjectCallable().call(request);
+   *   for (ReadObjectResponse response : stream) {
+   *     // Do something when a response is received.
+   *   }
+   * }
+   * }</pre>
+   */
+  public final ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> readObjectCallable() {
+    return stub.readObjectCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Stores a new object and metadata.
+   *
+   * <p>An object can be written either in a single message stream or in a resumable sequence of
+   * message streams. To write using a single stream, the client should include in the first message
+   * of the stream an `WriteObjectSpec` describing the destination bucket, object, and any
+   * preconditions. Additionally, the final message must set 'finish_write' to true, or else it is
+   * an error.
+   *
+   * <p>For a resumable write, the client should instead call `StartResumableWrite()` and provide
+   * that method an `WriteObjectSpec.` They should then attach the returned `upload_id` to the first
+   * message of each following call to `Create`. If there is an error or the connection is broken
+   * during the resumable `Create()`, the client should check the status of the `Create()` by
+   * calling `QueryWriteStatus()` and continue writing from the returned `committed_size`. This may
+   * be less than the amount of data the client previously sent.
+   *
+   * <p>The service will not view the object as complete until the client has sent a
+   * `WriteObjectRequest` with `finish_write` set to `true`. Sending any requests on a stream after
+   * sending a request with `finish_write` set to `true` will cause an error. The client
+   * &#42;&#42;should&#42;&#42; check the response it receives to determine how much data the
+   * service was able to commit and whether the service views the object as complete.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   ApiStreamObserver<WriteObjectRequest> responseObserver =
+   *       new ApiStreamObserver<WriteObjectRequest>() {
+   *         {@literal @}Override
+   *         public void onNext(WriteObjectResponse response) {
+   *           // Do something when a response is received.
+   *         }
+   *
+   *         {@literal @}Override
+   *         public void onError(Throwable t) {
+   *           // Add error-handling
+   *         }
+   *
+   *         {@literal @}Override
+   *         public void onCompleted() {
+   *           // Do something when complete.
+   *         }
+   *       };
+   *   ApiStreamObserver<WriteObjectRequest> requestObserver =
+   *       storageClient.writeObject().clientStreamingCall(responseObserver);
+   *   WriteObjectRequest request =
+   *       WriteObjectRequest.newBuilder()
+   *           .setWriteOffset(-1559543565)
+   *           .setObjectChecksums(ObjectChecksums.newBuilder().build())
+   *           .setFinishWrite(true)
+   *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+   *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+   *           .build();
+   *   requestObserver.onNext(request);
+   * }
+   * }</pre>
+   */
+  public final ClientStreamingCallable<WriteObjectRequest, WriteObjectResponse>
+      writeObjectCallable() {
+    return stub.writeObjectCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Starts a resumable write. How long the write operation remains valid, and what happens when the
+   * write operation becomes invalid, are service-dependent.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   StartResumableWriteRequest request =
+   *       StartResumableWriteRequest.newBuilder()
+   *           .setWriteObjectSpec(WriteObjectSpec.newBuilder().build())
+   *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+   *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+   *           .build();
+   *   StartResumableWriteResponse response = storageClient.startResumableWrite(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final StartResumableWriteResponse startResumableWrite(StartResumableWriteRequest request) {
+    return startResumableWriteCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Starts a resumable write. How long the write operation remains valid, and what happens when the
+   * write operation becomes invalid, are service-dependent.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   StartResumableWriteRequest request =
+   *       StartResumableWriteRequest.newBuilder()
+   *           .setWriteObjectSpec(WriteObjectSpec.newBuilder().build())
+   *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+   *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+   *           .build();
+   *   ApiFuture<StartResumableWriteResponse> future =
+   *       storageClient.startResumableWriteCallable().futureCall(request);
+   *   // Do something.
+   *   StartResumableWriteResponse response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteCallable() {
+    return stub.startResumableWriteCallable();
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Determines the `committed_size` for an object that is being written, which can then be used as
+   * the `write_offset` for the next `Write()` call.
+   *
+   * <p>If the object does not exist (i.e., the object has been deleted, or the first `Write()` has
+   * not yet reached the service), this method returns the error `NOT_FOUND`.
+   *
+   * <p>The client &#42;&#42;may&#42;&#42; call `QueryWriteStatus()` at any time to determine how
+   * much data has been processed for this object. This is useful if the client is buffering data
+   * and needs to know which data can be safely evicted. For any sequence of `QueryWriteStatus()`
+   * calls for a given object name, the sequence of returned `committed_size` values will be
+   * non-decreasing.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   String uploadId = "uploadId1563990780";
+   *   QueryWriteStatusResponse response = storageClient.queryWriteStatus(uploadId);
+   * }
+   * }</pre>
+   *
+   * @param uploadId Required. The name of the resume token for the object whose write status is
+   *     being requested.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final QueryWriteStatusResponse queryWriteStatus(String uploadId) {
+    QueryWriteStatusRequest request =
+        QueryWriteStatusRequest.newBuilder().setUploadId(uploadId).build();
+    return queryWriteStatus(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Determines the `committed_size` for an object that is being written, which can then be used as
+   * the `write_offset` for the next `Write()` call.
+   *
+   * <p>If the object does not exist (i.e., the object has been deleted, or the first `Write()` has
+   * not yet reached the service), this method returns the error `NOT_FOUND`.
+   *
+   * <p>The client &#42;&#42;may&#42;&#42; call `QueryWriteStatus()` at any time to determine how
+   * much data has been processed for this object. This is useful if the client is buffering data
+   * and needs to know which data can be safely evicted. For any sequence of `QueryWriteStatus()`
+   * calls for a given object name, the sequence of returned `committed_size` values will be
+   * non-decreasing.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   QueryWriteStatusRequest request =
+   *       QueryWriteStatusRequest.newBuilder()
+   *           .setUploadId("uploadId1563990780")
+   *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+   *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+   *           .build();
+   *   QueryWriteStatusResponse response = storageClient.queryWriteStatus(request);
+   * }
+   * }</pre>
+   *
+   * @param request The request object containing all of the parameters for the API call.
+   * @throws com.google.api.gax.rpc.ApiException if the remote call fails
+   */
+  public final QueryWriteStatusResponse queryWriteStatus(QueryWriteStatusRequest request) {
+    return queryWriteStatusCallable().call(request);
+  }
+
+  // AUTO-GENERATED DOCUMENTATION AND METHOD.
+  /**
+   * Determines the `committed_size` for an object that is being written, which can then be used as
+   * the `write_offset` for the next `Write()` call.
+   *
+   * <p>If the object does not exist (i.e., the object has been deleted, or the first `Write()` has
+   * not yet reached the service), this method returns the error `NOT_FOUND`.
+   *
+   * <p>The client &#42;&#42;may&#42;&#42; call `QueryWriteStatus()` at any time to determine how
+   * much data has been processed for this object. This is useful if the client is buffering data
+   * and needs to know which data can be safely evicted. For any sequence of `QueryWriteStatus()`
+   * calls for a given object name, the sequence of returned `committed_size` values will be
+   * non-decreasing.
+   *
+   * <p>Sample code:
+   *
+   * <pre>{@code
+   * try (StorageClient storageClient = StorageClient.create()) {
+   *   QueryWriteStatusRequest request =
+   *       QueryWriteStatusRequest.newBuilder()
+   *           .setUploadId("uploadId1563990780")
+   *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+   *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+   *           .build();
+   *   ApiFuture<QueryWriteStatusResponse> future =
+   *       storageClient.queryWriteStatusCallable().futureCall(request);
+   *   // Do something.
+   *   QueryWriteStatusResponse response = future.get();
+   * }
+   * }</pre>
+   */
+  public final UnaryCallable<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusCallable() {
+    return stub.queryWriteStatusCallable();
+  }
+
+  @Override
+  public final void close() {
+    stub.close();
+  }
+
+  @Override
+  public void shutdown() {
+    stub.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return stub.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return stub.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    stub.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return stub.awaitTermination(duration, unit);
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/StorageClientTest.java b/test/integration/goldens/storage/com/google/storage/v2/StorageClientTest.java
new file mode 100644
index 0000000000..6374e98e7a
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/StorageClientTest.java
@@ -0,0 +1,301 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2;
+
+import com.google.api.gax.core.NoCredentialsProvider;
+import com.google.api.gax.grpc.GaxGrpcProperties;
+import com.google.api.gax.grpc.testing.LocalChannelProvider;
+import com.google.api.gax.grpc.testing.MockGrpcService;
+import com.google.api.gax.grpc.testing.MockServiceHelper;
+import com.google.api.gax.grpc.testing.MockStreamObserver;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ApiStreamObserver;
+import com.google.api.gax.rpc.ClientStreamingCallable;
+import com.google.api.gax.rpc.InvalidArgumentException;
+import com.google.api.gax.rpc.ServerStreamingCallable;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.protobuf.AbstractMessage;
+import com.google.protobuf.FieldMask;
+import io.grpc.StatusRuntimeException;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import javax.annotation.Generated;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+@Generated("by gapic-generator-java")
+public class StorageClientTest {
+  private static MockServiceHelper mockServiceHelper;
+  private static MockStorage mockStorage;
+  private LocalChannelProvider channelProvider;
+  private StorageClient client;
+
+  @BeforeClass
+  public static void startStaticServer() {
+    mockStorage = new MockStorage();
+    mockServiceHelper =
+        new MockServiceHelper(
+            UUID.randomUUID().toString(), Arrays.<MockGrpcService>asList(mockStorage));
+    mockServiceHelper.start();
+  }
+
+  @AfterClass
+  public static void stopServer() {
+    mockServiceHelper.stop();
+  }
+
+  @Before
+  public void setUp() throws IOException {
+    mockServiceHelper.reset();
+    channelProvider = mockServiceHelper.createChannelProvider();
+    StorageSettings settings =
+        StorageSettings.newBuilder()
+            .setTransportChannelProvider(channelProvider)
+            .setCredentialsProvider(NoCredentialsProvider.create())
+            .build();
+    client = StorageClient.create(settings);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    client.close();
+  }
+
+  @Test
+  public void readObjectTest() throws Exception {
+    ReadObjectResponse expectedResponse =
+        ReadObjectResponse.newBuilder()
+            .setChecksummedData(ChecksummedData.newBuilder().build())
+            .setObjectChecksums(ObjectChecksums.newBuilder().build())
+            .setContentRange(ContentRange.newBuilder().build())
+            .setMetadata(Object.newBuilder().build())
+            .build();
+    mockStorage.addResponse(expectedResponse);
+    ReadObjectRequest request =
+        ReadObjectRequest.newBuilder()
+            .setBucket("bucket-1378203158")
+            .setObject("object-1023368385")
+            .setGeneration(305703192)
+            .setReadOffset(-715377828)
+            .setReadLimit(-164298798)
+            .setIfGenerationMatch(-1086241088)
+            .setIfGenerationNotMatch(1475720404)
+            .setIfMetagenerationMatch(1043427781)
+            .setIfMetagenerationNotMatch(1025430873)
+            .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+            .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+            .setReadMask(FieldMask.newBuilder().build())
+            .build();
+
+    MockStreamObserver<ReadObjectResponse> responseObserver = new MockStreamObserver<>();
+
+    ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> callable =
+        client.readObjectCallable();
+    callable.serverStreamingCall(request, responseObserver);
+
+    List<ReadObjectResponse> actualResponses = responseObserver.future().get();
+    Assert.assertEquals(1, actualResponses.size());
+    Assert.assertEquals(expectedResponse, actualResponses.get(0));
+  }
+
+  @Test
+  public void readObjectExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockStorage.addException(exception);
+    ReadObjectRequest request =
+        ReadObjectRequest.newBuilder()
+            .setBucket("bucket-1378203158")
+            .setObject("object-1023368385")
+            .setGeneration(305703192)
+            .setReadOffset(-715377828)
+            .setReadLimit(-164298798)
+            .setIfGenerationMatch(-1086241088)
+            .setIfGenerationNotMatch(1475720404)
+            .setIfMetagenerationMatch(1043427781)
+            .setIfMetagenerationNotMatch(1025430873)
+            .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+            .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+            .setReadMask(FieldMask.newBuilder().build())
+            .build();
+
+    MockStreamObserver<ReadObjectResponse> responseObserver = new MockStreamObserver<>();
+
+    ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> callable =
+        client.readObjectCallable();
+    callable.serverStreamingCall(request, responseObserver);
+
+    try {
+      List<ReadObjectResponse> actualResponses = responseObserver.future().get();
+      Assert.fail("No exception thrown");
+    } catch (ExecutionException e) {
+      Assert.assertTrue(e.getCause() instanceof InvalidArgumentException);
+      InvalidArgumentException apiException = ((InvalidArgumentException) e.getCause());
+      Assert.assertEquals(StatusCode.Code.INVALID_ARGUMENT, apiException.getStatusCode().getCode());
+    }
+  }
+
+  @Test
+  public void writeObjectTest() throws Exception {
+    WriteObjectResponse expectedResponse = WriteObjectResponse.newBuilder().build();
+    mockStorage.addResponse(expectedResponse);
+    WriteObjectRequest request =
+        WriteObjectRequest.newBuilder()
+            .setWriteOffset(-1559543565)
+            .setObjectChecksums(ObjectChecksums.newBuilder().build())
+            .setFinishWrite(true)
+            .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+            .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+            .build();
+
+    MockStreamObserver<WriteObjectResponse> responseObserver = new MockStreamObserver<>();
+
+    ClientStreamingCallable<WriteObjectRequest, WriteObjectResponse> callable =
+        client.writeObjectCallable();
+    ApiStreamObserver<WriteObjectRequest> requestObserver =
+        callable.clientStreamingCall(responseObserver);
+
+    requestObserver.onNext(request);
+    requestObserver.onCompleted();
+
+    List<WriteObjectResponse> actualResponses = responseObserver.future().get();
+    Assert.assertEquals(1, actualResponses.size());
+    Assert.assertEquals(expectedResponse, actualResponses.get(0));
+  }
+
+  @Test
+  public void writeObjectExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockStorage.addException(exception);
+    WriteObjectRequest request =
+        WriteObjectRequest.newBuilder()
+            .setWriteOffset(-1559543565)
+            .setObjectChecksums(ObjectChecksums.newBuilder().build())
+            .setFinishWrite(true)
+            .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+            .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+            .build();
+
+    MockStreamObserver<WriteObjectResponse> responseObserver = new MockStreamObserver<>();
+
+    ClientStreamingCallable<WriteObjectRequest, WriteObjectResponse> callable =
+        client.writeObjectCallable();
+    ApiStreamObserver<WriteObjectRequest> requestObserver =
+        callable.clientStreamingCall(responseObserver);
+
+    requestObserver.onNext(request);
+
+    try {
+      List<WriteObjectResponse> actualResponses = responseObserver.future().get();
+      Assert.fail("No exception thrown");
+    } catch (ExecutionException e) {
+      Assert.assertTrue(e.getCause() instanceof InvalidArgumentException);
+      InvalidArgumentException apiException = ((InvalidArgumentException) e.getCause());
+      Assert.assertEquals(StatusCode.Code.INVALID_ARGUMENT, apiException.getStatusCode().getCode());
+    }
+  }
+
+  @Test
+  public void startResumableWriteTest() throws Exception {
+    StartResumableWriteResponse expectedResponse =
+        StartResumableWriteResponse.newBuilder().setUploadId("uploadId1563990780").build();
+    mockStorage.addResponse(expectedResponse);
+
+    StartResumableWriteRequest request =
+        StartResumableWriteRequest.newBuilder()
+            .setWriteObjectSpec(WriteObjectSpec.newBuilder().build())
+            .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+            .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+            .build();
+
+    StartResumableWriteResponse actualResponse = client.startResumableWrite(request);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockStorage.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    StartResumableWriteRequest actualRequest = ((StartResumableWriteRequest) actualRequests.get(0));
+
+    Assert.assertEquals(request.getWriteObjectSpec(), actualRequest.getWriteObjectSpec());
+    Assert.assertEquals(
+        request.getCommonObjectRequestParams(), actualRequest.getCommonObjectRequestParams());
+    Assert.assertEquals(request.getCommonRequestParams(), actualRequest.getCommonRequestParams());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void startResumableWriteExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockStorage.addException(exception);
+
+    try {
+      StartResumableWriteRequest request =
+          StartResumableWriteRequest.newBuilder()
+              .setWriteObjectSpec(WriteObjectSpec.newBuilder().build())
+              .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+              .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+              .build();
+      client.startResumableWrite(request);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+
+  @Test
+  public void queryWriteStatusTest() throws Exception {
+    QueryWriteStatusResponse expectedResponse = QueryWriteStatusResponse.newBuilder().build();
+    mockStorage.addResponse(expectedResponse);
+
+    String uploadId = "uploadId1563990780";
+
+    QueryWriteStatusResponse actualResponse = client.queryWriteStatus(uploadId);
+    Assert.assertEquals(expectedResponse, actualResponse);
+
+    List<AbstractMessage> actualRequests = mockStorage.getRequests();
+    Assert.assertEquals(1, actualRequests.size());
+    QueryWriteStatusRequest actualRequest = ((QueryWriteStatusRequest) actualRequests.get(0));
+
+    Assert.assertEquals(uploadId, actualRequest.getUploadId());
+    Assert.assertTrue(
+        channelProvider.isHeaderSent(
+            ApiClientHeaderProvider.getDefaultApiClientHeaderKey(),
+            GaxGrpcProperties.getDefaultApiClientHeaderPattern()));
+  }
+
+  @Test
+  public void queryWriteStatusExceptionTest() throws Exception {
+    StatusRuntimeException exception = new StatusRuntimeException(io.grpc.Status.INVALID_ARGUMENT);
+    mockStorage.addException(exception);
+
+    try {
+      String uploadId = "uploadId1563990780";
+      client.queryWriteStatus(uploadId);
+      Assert.fail("No exception raised");
+    } catch (InvalidArgumentException e) {
+      // Expected exception.
+    }
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/StorageSettings.java b/test/integration/goldens/storage/com/google/storage/v2/StorageSettings.java
new file mode 100644
index 0000000000..8cbe00e72f
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/StorageSettings.java
@@ -0,0 +1,218 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientSettings;
+import com.google.api.gax.rpc.ServerStreamingCallSettings;
+import com.google.api.gax.rpc.StreamingCallSettings;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.storage.v2.stub.StorageStubSettings;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link StorageClient}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (storage.googleapis.com) and default port (443) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of startResumableWrite to 30 seconds:
+ *
+ * <pre>{@code
+ * StorageSettings.Builder storageSettingsBuilder = StorageSettings.newBuilder();
+ * storageSettingsBuilder
+ *     .startResumableWriteSettings()
+ *     .setRetrySettings(
+ *         storageSettingsBuilder
+ *             .startResumableWriteSettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * StorageSettings storageSettings = storageSettingsBuilder.build();
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+public class StorageSettings extends ClientSettings<StorageSettings> {
+
+  /** Returns the object with the settings used for calls to readObject. */
+  public ServerStreamingCallSettings<ReadObjectRequest, ReadObjectResponse> readObjectSettings() {
+    return ((StorageStubSettings) getStubSettings()).readObjectSettings();
+  }
+
+  /** Returns the object with the settings used for calls to writeObject. */
+  public StreamingCallSettings<WriteObjectRequest, WriteObjectResponse> writeObjectSettings() {
+    return ((StorageStubSettings) getStubSettings()).writeObjectSettings();
+  }
+
+  /** Returns the object with the settings used for calls to startResumableWrite. */
+  public UnaryCallSettings<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteSettings() {
+    return ((StorageStubSettings) getStubSettings()).startResumableWriteSettings();
+  }
+
+  /** Returns the object with the settings used for calls to queryWriteStatus. */
+  public UnaryCallSettings<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusSettings() {
+    return ((StorageStubSettings) getStubSettings()).queryWriteStatusSettings();
+  }
+
+  public static final StorageSettings create(StorageStubSettings stub) throws IOException {
+    return new StorageSettings.Builder(stub.toBuilder()).build();
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return StorageStubSettings.defaultExecutorProviderBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return StorageStubSettings.getDefaultEndpoint();
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return StorageStubSettings.getDefaultServiceScopes();
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return StorageStubSettings.defaultCredentialsProviderBuilder();
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingGrpcChannelProvider.Builder defaultGrpcTransportProviderBuilder() {
+    return StorageStubSettings.defaultGrpcTransportProviderBuilder();
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return StorageStubSettings.defaultTransportChannelProvider();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return StorageStubSettings.defaultApiClientHeaderProviderBuilder();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected StorageSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+  }
+
+  /** Builder for StorageSettings. */
+  public static class Builder extends ClientSettings.Builder<StorageSettings, Builder> {
+
+    protected Builder() throws IOException {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(StorageStubSettings.newBuilder(clientContext));
+    }
+
+    protected Builder(StorageSettings settings) {
+      super(settings.getStubSettings().toBuilder());
+    }
+
+    protected Builder(StorageStubSettings.Builder stubSettings) {
+      super(stubSettings);
+    }
+
+    private static Builder createDefault() {
+      return new Builder(StorageStubSettings.newBuilder());
+    }
+
+    public StorageStubSettings.Builder getStubSettingsBuilder() {
+      return ((StorageStubSettings.Builder) getStubSettings());
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(
+          getStubSettingsBuilder().unaryMethodSettingsBuilders(), settingsUpdater);
+      return this;
+    }
+
+    /** Returns the builder for the settings used for calls to readObject. */
+    public ServerStreamingCallSettings.Builder<ReadObjectRequest, ReadObjectResponse>
+        readObjectSettings() {
+      return getStubSettingsBuilder().readObjectSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to writeObject. */
+    public StreamingCallSettings.Builder<WriteObjectRequest, WriteObjectResponse>
+        writeObjectSettings() {
+      return getStubSettingsBuilder().writeObjectSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to startResumableWrite. */
+    public UnaryCallSettings.Builder<StartResumableWriteRequest, StartResumableWriteResponse>
+        startResumableWriteSettings() {
+      return getStubSettingsBuilder().startResumableWriteSettings();
+    }
+
+    /** Returns the builder for the settings used for calls to queryWriteStatus. */
+    public UnaryCallSettings.Builder<QueryWriteStatusRequest, QueryWriteStatusResponse>
+        queryWriteStatusSettings() {
+      return getStubSettingsBuilder().queryWriteStatusSettings();
+    }
+
+    @Override
+    public StorageSettings build() throws IOException {
+      return new StorageSettings(this);
+    }
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/gapic_metadata.json b/test/integration/goldens/storage/com/google/storage/v2/gapic_metadata.json
new file mode 100644
index 0000000000..a9899e16f9
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/gapic_metadata.json
@@ -0,0 +1,30 @@
+{
+  "schema": "1.0",
+  "comment": "This file maps proto services/RPCs to the corresponding library clients/methods",
+  "language": "java",
+  "protoPackage": "google.storage.v2",
+  "libraryPackage": "com.google.storage.v2",
+  "services": {
+    "Storage": {
+      "clients": {
+        "grpc": {
+          "libraryClient": "StorageClient",
+          "rpcs": {
+            "QueryWriteStatus": {
+              "methods": ["queryWriteStatus", "queryWriteStatus", "queryWriteStatusCallable"]
+            },
+            "ReadObject": {
+              "methods": ["readObjectCallable"]
+            },
+            "StartResumableWrite": {
+              "methods": ["startResumableWrite", "startResumableWriteCallable"]
+            },
+            "WriteObject": {
+              "methods": ["writeObjectCallable"]
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/test/integration/goldens/storage/com/google/storage/v2/package-info.java b/test/integration/goldens/storage/com/google/storage/v2/package-info.java
new file mode 100644
index 0000000000..bfb389cc80
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/package-info.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * The interfaces provided are listed below, along with usage samples.
+ *
+ * <p>======================= StorageClient =======================
+ *
+ * <p>Service Description: Manages Google Cloud Storage resources.
+ *
+ * <p>Sample for StorageClient:
+ *
+ * <pre>{@code
+ * try (StorageClient storageClient = StorageClient.create()) {
+ *   StartResumableWriteRequest request =
+ *       StartResumableWriteRequest.newBuilder()
+ *           .setWriteObjectSpec(WriteObjectSpec.newBuilder().build())
+ *           .setCommonObjectRequestParams(CommonObjectRequestParams.newBuilder().build())
+ *           .setCommonRequestParams(CommonRequestParams.newBuilder().build())
+ *           .build();
+ *   StartResumableWriteResponse response = storageClient.startResumableWrite(request);
+ * }
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+package com.google.storage.v2;
+
+import javax.annotation.Generated;
diff --git a/test/integration/goldens/storage/com/google/storage/v2/stub/GrpcStorageCallableFactory.java b/test/integration/goldens/storage/com/google/storage/v2/stub/GrpcStorageCallableFactory.java
new file mode 100644
index 0000000000..47ef05368a
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/stub/GrpcStorageCallableFactory.java
@@ -0,0 +1,113 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2.stub;
+
+import com.google.api.gax.grpc.GrpcCallSettings;
+import com.google.api.gax.grpc.GrpcCallableFactory;
+import com.google.api.gax.grpc.GrpcStubCallableFactory;
+import com.google.api.gax.rpc.BatchingCallSettings;
+import com.google.api.gax.rpc.BidiStreamingCallable;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientStreamingCallable;
+import com.google.api.gax.rpc.OperationCallSettings;
+import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.PagedCallSettings;
+import com.google.api.gax.rpc.ServerStreamingCallSettings;
+import com.google.api.gax.rpc.ServerStreamingCallable;
+import com.google.api.gax.rpc.StreamingCallSettings;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.longrunning.Operation;
+import com.google.longrunning.stub.OperationsStub;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * gRPC callable factory implementation for the Storage service API.
+ *
+ * <p>This class is for advanced usage.
+ */
+@Generated("by gapic-generator-java")
+public class GrpcStorageCallableFactory implements GrpcStubCallableFactory {
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
+      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
+      UnaryCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return GrpcCallableFactory.createUnaryCallable(grpcCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT, PagedListResponseT>
+      UnaryCallable<RequestT, PagedListResponseT> createPagedCallable(
+          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
+          PagedCallSettings<RequestT, ResponseT, PagedListResponseT> callSettings,
+          ClientContext clientContext) {
+    return GrpcCallableFactory.createPagedCallable(grpcCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createBatchingCallable(
+      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
+      BatchingCallSettings<RequestT, ResponseT> callSettings,
+      ClientContext clientContext) {
+    return GrpcCallableFactory.createBatchingCallable(
+        grpcCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT, MetadataT>
+      OperationCallable<RequestT, ResponseT, MetadataT> createOperationCallable(
+          GrpcCallSettings<RequestT, Operation> grpcCallSettings,
+          OperationCallSettings<RequestT, ResponseT, MetadataT> callSettings,
+          ClientContext clientContext,
+          OperationsStub operationsStub) {
+    return GrpcCallableFactory.createOperationCallable(
+        grpcCallSettings, callSettings, clientContext, operationsStub);
+  }
+
+  @Override
+  public <RequestT, ResponseT>
+      BidiStreamingCallable<RequestT, ResponseT> createBidiStreamingCallable(
+          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
+          StreamingCallSettings<RequestT, ResponseT> callSettings,
+          ClientContext clientContext) {
+    return GrpcCallableFactory.createBidiStreamingCallable(
+        grpcCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT>
+      ServerStreamingCallable<RequestT, ResponseT> createServerStreamingCallable(
+          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
+          ServerStreamingCallSettings<RequestT, ResponseT> callSettings,
+          ClientContext clientContext) {
+    return GrpcCallableFactory.createServerStreamingCallable(
+        grpcCallSettings, callSettings, clientContext);
+  }
+
+  @Override
+  public <RequestT, ResponseT>
+      ClientStreamingCallable<RequestT, ResponseT> createClientStreamingCallable(
+          GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
+          StreamingCallSettings<RequestT, ResponseT> callSettings,
+          ClientContext clientContext) {
+    return GrpcCallableFactory.createClientStreamingCallable(
+        grpcCallSettings, callSettings, clientContext);
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/stub/GrpcStorageStub.java b/test/integration/goldens/storage/com/google/storage/v2/stub/GrpcStorageStub.java
new file mode 100644
index 0000000000..3097e32c82
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/stub/GrpcStorageStub.java
@@ -0,0 +1,237 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2.stub;
+
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.core.BackgroundResourceAggregation;
+import com.google.api.gax.grpc.GrpcCallSettings;
+import com.google.api.gax.grpc.GrpcStubCallableFactory;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ClientStreamingCallable;
+import com.google.api.gax.rpc.ServerStreamingCallable;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.longrunning.stub.GrpcOperationsStub;
+import com.google.storage.v2.QueryWriteStatusRequest;
+import com.google.storage.v2.QueryWriteStatusResponse;
+import com.google.storage.v2.ReadObjectRequest;
+import com.google.storage.v2.ReadObjectResponse;
+import com.google.storage.v2.StartResumableWriteRequest;
+import com.google.storage.v2.StartResumableWriteResponse;
+import com.google.storage.v2.WriteObjectRequest;
+import com.google.storage.v2.WriteObjectResponse;
+import io.grpc.MethodDescriptor;
+import io.grpc.protobuf.ProtoUtils;
+import java.io.IOException;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * gRPC stub implementation for the Storage service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@Generated("by gapic-generator-java")
+public class GrpcStorageStub extends StorageStub {
+  private static final MethodDescriptor<ReadObjectRequest, ReadObjectResponse>
+      readObjectMethodDescriptor =
+          MethodDescriptor.<ReadObjectRequest, ReadObjectResponse>newBuilder()
+              .setType(MethodDescriptor.MethodType.SERVER_STREAMING)
+              .setFullMethodName("google.storage.v2.Storage/ReadObject")
+              .setRequestMarshaller(ProtoUtils.marshaller(ReadObjectRequest.getDefaultInstance()))
+              .setResponseMarshaller(ProtoUtils.marshaller(ReadObjectResponse.getDefaultInstance()))
+              .build();
+
+  private static final MethodDescriptor<WriteObjectRequest, WriteObjectResponse>
+      writeObjectMethodDescriptor =
+          MethodDescriptor.<WriteObjectRequest, WriteObjectResponse>newBuilder()
+              .setType(MethodDescriptor.MethodType.CLIENT_STREAMING)
+              .setFullMethodName("google.storage.v2.Storage/WriteObject")
+              .setRequestMarshaller(ProtoUtils.marshaller(WriteObjectRequest.getDefaultInstance()))
+              .setResponseMarshaller(
+                  ProtoUtils.marshaller(WriteObjectResponse.getDefaultInstance()))
+              .build();
+
+  private static final MethodDescriptor<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteMethodDescriptor =
+          MethodDescriptor.<StartResumableWriteRequest, StartResumableWriteResponse>newBuilder()
+              .setType(MethodDescriptor.MethodType.UNARY)
+              .setFullMethodName("google.storage.v2.Storage/StartResumableWrite")
+              .setRequestMarshaller(
+                  ProtoUtils.marshaller(StartResumableWriteRequest.getDefaultInstance()))
+              .setResponseMarshaller(
+                  ProtoUtils.marshaller(StartResumableWriteResponse.getDefaultInstance()))
+              .build();
+
+  private static final MethodDescriptor<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusMethodDescriptor =
+          MethodDescriptor.<QueryWriteStatusRequest, QueryWriteStatusResponse>newBuilder()
+              .setType(MethodDescriptor.MethodType.UNARY)
+              .setFullMethodName("google.storage.v2.Storage/QueryWriteStatus")
+              .setRequestMarshaller(
+                  ProtoUtils.marshaller(QueryWriteStatusRequest.getDefaultInstance()))
+              .setResponseMarshaller(
+                  ProtoUtils.marshaller(QueryWriteStatusResponse.getDefaultInstance()))
+              .build();
+
+  private final ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> readObjectCallable;
+  private final ClientStreamingCallable<WriteObjectRequest, WriteObjectResponse>
+      writeObjectCallable;
+  private final UnaryCallable<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteCallable;
+  private final UnaryCallable<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusCallable;
+
+  private final BackgroundResource backgroundResources;
+  private final GrpcOperationsStub operationsStub;
+  private final GrpcStubCallableFactory callableFactory;
+
+  public static final GrpcStorageStub create(StorageStubSettings settings) throws IOException {
+    return new GrpcStorageStub(settings, ClientContext.create(settings));
+  }
+
+  public static final GrpcStorageStub create(ClientContext clientContext) throws IOException {
+    return new GrpcStorageStub(StorageStubSettings.newBuilder().build(), clientContext);
+  }
+
+  public static final GrpcStorageStub create(
+      ClientContext clientContext, GrpcStubCallableFactory callableFactory) throws IOException {
+    return new GrpcStorageStub(
+        StorageStubSettings.newBuilder().build(), clientContext, callableFactory);
+  }
+
+  /**
+   * Constructs an instance of GrpcStorageStub, using the given settings. This is protected so that
+   * it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
+   */
+  protected GrpcStorageStub(StorageStubSettings settings, ClientContext clientContext)
+      throws IOException {
+    this(settings, clientContext, new GrpcStorageCallableFactory());
+  }
+
+  /**
+   * Constructs an instance of GrpcStorageStub, using the given settings. This is protected so that
+   * it is easy to make a subclass, but otherwise, the static factory methods should be preferred.
+   */
+  protected GrpcStorageStub(
+      StorageStubSettings settings,
+      ClientContext clientContext,
+      GrpcStubCallableFactory callableFactory)
+      throws IOException {
+    this.callableFactory = callableFactory;
+    this.operationsStub = GrpcOperationsStub.create(clientContext, callableFactory);
+
+    GrpcCallSettings<ReadObjectRequest, ReadObjectResponse> readObjectTransportSettings =
+        GrpcCallSettings.<ReadObjectRequest, ReadObjectResponse>newBuilder()
+            .setMethodDescriptor(readObjectMethodDescriptor)
+            .build();
+    GrpcCallSettings<WriteObjectRequest, WriteObjectResponse> writeObjectTransportSettings =
+        GrpcCallSettings.<WriteObjectRequest, WriteObjectResponse>newBuilder()
+            .setMethodDescriptor(writeObjectMethodDescriptor)
+            .build();
+    GrpcCallSettings<StartResumableWriteRequest, StartResumableWriteResponse>
+        startResumableWriteTransportSettings =
+            GrpcCallSettings.<StartResumableWriteRequest, StartResumableWriteResponse>newBuilder()
+                .setMethodDescriptor(startResumableWriteMethodDescriptor)
+                .build();
+    GrpcCallSettings<QueryWriteStatusRequest, QueryWriteStatusResponse>
+        queryWriteStatusTransportSettings =
+            GrpcCallSettings.<QueryWriteStatusRequest, QueryWriteStatusResponse>newBuilder()
+                .setMethodDescriptor(queryWriteStatusMethodDescriptor)
+                .build();
+
+    this.readObjectCallable =
+        callableFactory.createServerStreamingCallable(
+            readObjectTransportSettings, settings.readObjectSettings(), clientContext);
+    this.writeObjectCallable =
+        callableFactory.createClientStreamingCallable(
+            writeObjectTransportSettings, settings.writeObjectSettings(), clientContext);
+    this.startResumableWriteCallable =
+        callableFactory.createUnaryCallable(
+            startResumableWriteTransportSettings,
+            settings.startResumableWriteSettings(),
+            clientContext);
+    this.queryWriteStatusCallable =
+        callableFactory.createUnaryCallable(
+            queryWriteStatusTransportSettings, settings.queryWriteStatusSettings(), clientContext);
+
+    this.backgroundResources =
+        new BackgroundResourceAggregation(clientContext.getBackgroundResources());
+  }
+
+  public GrpcOperationsStub getOperationsStub() {
+    return operationsStub;
+  }
+
+  @Override
+  public ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> readObjectCallable() {
+    return readObjectCallable;
+  }
+
+  @Override
+  public ClientStreamingCallable<WriteObjectRequest, WriteObjectResponse> writeObjectCallable() {
+    return writeObjectCallable;
+  }
+
+  @Override
+  public UnaryCallable<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteCallable() {
+    return startResumableWriteCallable;
+  }
+
+  @Override
+  public UnaryCallable<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusCallable() {
+    return queryWriteStatusCallable;
+  }
+
+  @Override
+  public final void close() {
+    try {
+      backgroundResources.close();
+    } catch (RuntimeException e) {
+      throw e;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to close resource", e);
+    }
+  }
+
+  @Override
+  public void shutdown() {
+    backgroundResources.shutdown();
+  }
+
+  @Override
+  public boolean isShutdown() {
+    return backgroundResources.isShutdown();
+  }
+
+  @Override
+  public boolean isTerminated() {
+    return backgroundResources.isTerminated();
+  }
+
+  @Override
+  public void shutdownNow() {
+    backgroundResources.shutdownNow();
+  }
+
+  @Override
+  public boolean awaitTermination(long duration, TimeUnit unit) throws InterruptedException {
+    return backgroundResources.awaitTermination(duration, unit);
+  }
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/stub/StorageStub.java b/test/integration/goldens/storage/com/google/storage/v2/stub/StorageStub.java
new file mode 100644
index 0000000000..06ee713906
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/stub/StorageStub.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2.stub;
+
+import com.google.api.gax.core.BackgroundResource;
+import com.google.api.gax.rpc.ClientStreamingCallable;
+import com.google.api.gax.rpc.ServerStreamingCallable;
+import com.google.api.gax.rpc.UnaryCallable;
+import com.google.storage.v2.QueryWriteStatusRequest;
+import com.google.storage.v2.QueryWriteStatusResponse;
+import com.google.storage.v2.ReadObjectRequest;
+import com.google.storage.v2.ReadObjectResponse;
+import com.google.storage.v2.StartResumableWriteRequest;
+import com.google.storage.v2.StartResumableWriteResponse;
+import com.google.storage.v2.WriteObjectRequest;
+import com.google.storage.v2.WriteObjectResponse;
+import javax.annotation.Generated;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Base stub class for the Storage service API.
+ *
+ * <p>This class is for advanced usage and reflects the underlying API directly.
+ */
+@Generated("by gapic-generator-java")
+public abstract class StorageStub implements BackgroundResource {
+
+  public ServerStreamingCallable<ReadObjectRequest, ReadObjectResponse> readObjectCallable() {
+    throw new UnsupportedOperationException("Not implemented: readObjectCallable()");
+  }
+
+  public ClientStreamingCallable<WriteObjectRequest, WriteObjectResponse> writeObjectCallable() {
+    throw new UnsupportedOperationException("Not implemented: writeObjectCallable()");
+  }
+
+  public UnaryCallable<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteCallable() {
+    throw new UnsupportedOperationException("Not implemented: startResumableWriteCallable()");
+  }
+
+  public UnaryCallable<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusCallable() {
+    throw new UnsupportedOperationException("Not implemented: queryWriteStatusCallable()");
+  }
+
+  @Override
+  public abstract void close();
+}
diff --git a/test/integration/goldens/storage/com/google/storage/v2/stub/StorageStubSettings.java b/test/integration/goldens/storage/com/google/storage/v2/stub/StorageStubSettings.java
new file mode 100644
index 0000000000..85c8639848
--- /dev/null
+++ b/test/integration/goldens/storage/com/google/storage/v2/stub/StorageStubSettings.java
@@ -0,0 +1,358 @@
+/*
+ * Copyright 2021 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.storage.v2.stub;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.core.BetaApi;
+import com.google.api.gax.core.GaxProperties;
+import com.google.api.gax.core.GoogleCredentialsProvider;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.grpc.GaxGrpcProperties;
+import com.google.api.gax.grpc.GrpcTransportChannel;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.retrying.RetrySettings;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.ClientContext;
+import com.google.api.gax.rpc.ServerStreamingCallSettings;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.StreamingCallSettings;
+import com.google.api.gax.rpc.StubSettings;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.google.storage.v2.QueryWriteStatusRequest;
+import com.google.storage.v2.QueryWriteStatusResponse;
+import com.google.storage.v2.ReadObjectRequest;
+import com.google.storage.v2.ReadObjectResponse;
+import com.google.storage.v2.StartResumableWriteRequest;
+import com.google.storage.v2.StartResumableWriteResponse;
+import com.google.storage.v2.WriteObjectRequest;
+import com.google.storage.v2.WriteObjectResponse;
+import java.io.IOException;
+import java.util.List;
+import javax.annotation.Generated;
+import org.threeten.bp.Duration;
+
+// AUTO-GENERATED DOCUMENTATION AND CLASS.
+/**
+ * Settings class to configure an instance of {@link StorageStub}.
+ *
+ * <p>The default instance has everything set to sensible defaults:
+ *
+ * <ul>
+ *   <li>The default service address (storage.googleapis.com) and default port (443) are used.
+ *   <li>Credentials are acquired automatically through Application Default Credentials.
+ *   <li>Retries are configured for idempotent methods but not for non-idempotent methods.
+ * </ul>
+ *
+ * <p>The builder of this class is recursive, so contained classes are themselves builders. When
+ * build() is called, the tree of builders is called to create the complete settings object.
+ *
+ * <p>For example, to set the total timeout of startResumableWrite to 30 seconds:
+ *
+ * <pre>{@code
+ * StorageStubSettings.Builder storageSettingsBuilder = StorageStubSettings.newBuilder();
+ * storageSettingsBuilder
+ *     .startResumableWriteSettings()
+ *     .setRetrySettings(
+ *         storageSettingsBuilder
+ *             .startResumableWriteSettings()
+ *             .getRetrySettings()
+ *             .toBuilder()
+ *             .setTotalTimeout(Duration.ofSeconds(30))
+ *             .build());
+ * StorageStubSettings storageSettings = storageSettingsBuilder.build();
+ * }</pre>
+ */
+@Generated("by gapic-generator-java")
+public class StorageStubSettings extends StubSettings<StorageStubSettings> {
+  /** The default scopes of the service. */
+  private static final ImmutableList<String> DEFAULT_SERVICE_SCOPES =
+      ImmutableList.<String>builder()
+          .add("https://www.googleapis.com/auth/cloud-platform")
+          .add("https://www.googleapis.com/auth/cloud-platform.read-only")
+          .add("https://www.googleapis.com/auth/devstorage.full_control")
+          .add("https://www.googleapis.com/auth/devstorage.read_only")
+          .add("https://www.googleapis.com/auth/devstorage.read_write")
+          .build();
+
+  private final ServerStreamingCallSettings<ReadObjectRequest, ReadObjectResponse>
+      readObjectSettings;
+  private final StreamingCallSettings<WriteObjectRequest, WriteObjectResponse> writeObjectSettings;
+  private final UnaryCallSettings<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteSettings;
+  private final UnaryCallSettings<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusSettings;
+
+  /** Returns the object with the settings used for calls to readObject. */
+  public ServerStreamingCallSettings<ReadObjectRequest, ReadObjectResponse> readObjectSettings() {
+    return readObjectSettings;
+  }
+
+  /** Returns the object with the settings used for calls to writeObject. */
+  public StreamingCallSettings<WriteObjectRequest, WriteObjectResponse> writeObjectSettings() {
+    return writeObjectSettings;
+  }
+
+  /** Returns the object with the settings used for calls to startResumableWrite. */
+  public UnaryCallSettings<StartResumableWriteRequest, StartResumableWriteResponse>
+      startResumableWriteSettings() {
+    return startResumableWriteSettings;
+  }
+
+  /** Returns the object with the settings used for calls to queryWriteStatus. */
+  public UnaryCallSettings<QueryWriteStatusRequest, QueryWriteStatusResponse>
+      queryWriteStatusSettings() {
+    return queryWriteStatusSettings;
+  }
+
+  @BetaApi("A restructuring of stub classes is planned, so this may break in the future")
+  public StorageStub createStub() throws IOException {
+    if (getTransportChannelProvider()
+        .getTransportName()
+        .equals(GrpcTransportChannel.getGrpcTransportName())) {
+      return GrpcStorageStub.create(this);
+    }
+    throw new UnsupportedOperationException(
+        String.format(
+            "Transport not supported: %s", getTransportChannelProvider().getTransportName()));
+  }
+
+  /** Returns a builder for the default ExecutorProvider for this service. */
+  public static InstantiatingExecutorProvider.Builder defaultExecutorProviderBuilder() {
+    return InstantiatingExecutorProvider.newBuilder();
+  }
+
+  /** Returns the default service endpoint. */
+  public static String getDefaultEndpoint() {
+    return "storage.googleapis.com:443";
+  }
+
+  /** Returns the default mTLS service endpoint. */
+  public static String getDefaultMtlsEndpoint() {
+    return "storage.mtls.googleapis.com:443";
+  }
+
+  /** Returns the default service scopes. */
+  public static List<String> getDefaultServiceScopes() {
+    return DEFAULT_SERVICE_SCOPES;
+  }
+
+  /** Returns a builder for the default credentials for this service. */
+  public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
+  }
+
+  /** Returns a builder for the default ChannelProvider for this service. */
+  public static InstantiatingGrpcChannelProvider.Builder defaultGrpcTransportProviderBuilder() {
+    return InstantiatingGrpcChannelProvider.newBuilder()
+        .setMaxInboundMessageSize(Integer.MAX_VALUE);
+  }
+
+  public static TransportChannelProvider defaultTransportChannelProvider() {
+    return defaultGrpcTransportProviderBuilder().build();
+  }
+
+  @BetaApi("The surface for customizing headers is not stable yet and may change in the future.")
+  public static ApiClientHeaderProvider.Builder defaultApiClientHeaderProviderBuilder() {
+    return ApiClientHeaderProvider.newBuilder()
+        .setGeneratedLibToken("gapic", GaxProperties.getLibraryVersion(StorageStubSettings.class))
+        .setTransportToken(
+            GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion());
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder() {
+    return Builder.createDefault();
+  }
+
+  /** Returns a new builder for this class. */
+  public static Builder newBuilder(ClientContext clientContext) {
+    return new Builder(clientContext);
+  }
+
+  /** Returns a builder containing all the values of this settings class. */
+  public Builder toBuilder() {
+    return new Builder(this);
+  }
+
+  protected StorageStubSettings(Builder settingsBuilder) throws IOException {
+    super(settingsBuilder);
+
+    readObjectSettings = settingsBuilder.readObjectSettings().build();
+    writeObjectSettings = settingsBuilder.writeObjectSettings().build();
+    startResumableWriteSettings = settingsBuilder.startResumableWriteSettings().build();
+    queryWriteStatusSettings = settingsBuilder.queryWriteStatusSettings().build();
+  }
+
+  /** Builder for StorageStubSettings. */
+  public static class Builder extends StubSettings.Builder<StorageStubSettings, Builder> {
+    private final ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders;
+    private final ServerStreamingCallSettings.Builder<ReadObjectRequest, ReadObjectResponse>
+        readObjectSettings;
+    private final StreamingCallSettings.Builder<WriteObjectRequest, WriteObjectResponse>
+        writeObjectSettings;
+    private final UnaryCallSettings.Builder<StartResumableWriteRequest, StartResumableWriteResponse>
+        startResumableWriteSettings;
+    private final UnaryCallSettings.Builder<QueryWriteStatusRequest, QueryWriteStatusResponse>
+        queryWriteStatusSettings;
+    private static final ImmutableMap<String, ImmutableSet<StatusCode.Code>>
+        RETRYABLE_CODE_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, ImmutableSet<StatusCode.Code>> definitions =
+          ImmutableMap.builder();
+      definitions.put(
+          "retry_policy_0_codes",
+          ImmutableSet.copyOf(
+              Lists.<StatusCode.Code>newArrayList(
+                  StatusCode.Code.DEADLINE_EXCEEDED, StatusCode.Code.UNAVAILABLE)));
+      RETRYABLE_CODE_DEFINITIONS = definitions.build();
+    }
+
+    private static final ImmutableMap<String, RetrySettings> RETRY_PARAM_DEFINITIONS;
+
+    static {
+      ImmutableMap.Builder<String, RetrySettings> definitions = ImmutableMap.builder();
+      RetrySettings settings = null;
+      settings =
+          RetrySettings.newBuilder()
+              .setInitialRetryDelay(Duration.ofMillis(1000L))
+              .setRetryDelayMultiplier(2.0)
+              .setMaxRetryDelay(Duration.ofMillis(60000L))
+              .setInitialRpcTimeout(Duration.ofMillis(60000L))
+              .setRpcTimeoutMultiplier(1.0)
+              .setMaxRpcTimeout(Duration.ofMillis(60000L))
+              .setTotalTimeout(Duration.ofMillis(60000L))
+              .build();
+      definitions.put("retry_policy_0_params", settings);
+      RETRY_PARAM_DEFINITIONS = definitions.build();
+    }
+
+    protected Builder() {
+      this(((ClientContext) null));
+    }
+
+    protected Builder(ClientContext clientContext) {
+      super(clientContext);
+
+      readObjectSettings = ServerStreamingCallSettings.newBuilder();
+      writeObjectSettings = StreamingCallSettings.newBuilder();
+      startResumableWriteSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+      queryWriteStatusSettings = UnaryCallSettings.newUnaryCallSettingsBuilder();
+
+      unaryMethodSettingsBuilders =
+          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
+              startResumableWriteSettings, queryWriteStatusSettings);
+      initDefaults(this);
+    }
+
+    protected Builder(StorageStubSettings settings) {
+      super(settings);
+
+      readObjectSettings = settings.readObjectSettings.toBuilder();
+      writeObjectSettings = settings.writeObjectSettings.toBuilder();
+      startResumableWriteSettings = settings.startResumableWriteSettings.toBuilder();
+      queryWriteStatusSettings = settings.queryWriteStatusSettings.toBuilder();
+
+      unaryMethodSettingsBuilders =
+          ImmutableList.<UnaryCallSettings.Builder<?, ?>>of(
+              startResumableWriteSettings, queryWriteStatusSettings);
+    }
+
+    private static Builder createDefault() {
+      Builder builder = new Builder(((ClientContext) null));
+
+      builder.setTransportChannelProvider(defaultTransportChannelProvider());
+      builder.setCredentialsProvider(defaultCredentialsProviderBuilder().build());
+      builder.setInternalHeaderProvider(defaultApiClientHeaderProviderBuilder().build());
+      builder.setEndpoint(getDefaultEndpoint());
+      builder.setMtlsEndpoint(getDefaultMtlsEndpoint());
+      builder.setSwitchToMtlsEndpointAllowed(true);
+
+      return initDefaults(builder);
+    }
+
+    private static Builder initDefaults(Builder builder) {
+      builder
+          .readObjectSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
+
+      builder
+          .startResumableWriteSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
+
+      builder
+          .queryWriteStatusSettings()
+          .setRetryableCodes(RETRYABLE_CODE_DEFINITIONS.get("retry_policy_0_codes"))
+          .setRetrySettings(RETRY_PARAM_DEFINITIONS.get("retry_policy_0_params"));
+
+      return builder;
+    }
+
+    /**
+     * Applies the given settings updater function to all of the unary API methods in this service.
+     *
+     * <p>Note: This method does not support applying settings to streaming methods.
+     */
+    public Builder applyToAllUnaryMethods(
+        ApiFunction<UnaryCallSettings.Builder<?, ?>, Void> settingsUpdater) {
+      super.applyToAllUnaryMethods(unaryMethodSettingsBuilders, settingsUpdater);
+      return this;
+    }
+
+    public ImmutableList<UnaryCallSettings.Builder<?, ?>> unaryMethodSettingsBuilders() {
+      return unaryMethodSettingsBuilders;
+    }
+
+    /** Returns the builder for the settings used for calls to readObject. */
+    public ServerStreamingCallSettings.Builder<ReadObjectRequest, ReadObjectResponse>
+        readObjectSettings() {
+      return readObjectSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to writeObject. */
+    public StreamingCallSettings.Builder<WriteObjectRequest, WriteObjectResponse>
+        writeObjectSettings() {
+      return writeObjectSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to startResumableWrite. */
+    public UnaryCallSettings.Builder<StartResumableWriteRequest, StartResumableWriteResponse>
+        startResumableWriteSettings() {
+      return startResumableWriteSettings;
+    }
+
+    /** Returns the builder for the settings used for calls to queryWriteStatus. */
+    public UnaryCallSettings.Builder<QueryWriteStatusRequest, QueryWriteStatusResponse>
+        queryWriteStatusSettings() {
+      return queryWriteStatusSettings;
+    }
+
+    @Override
+    public StorageStubSettings build() throws IOException {
+      return new StorageStubSettings(this);
+    }
+  }
+}
diff --git a/version.txt b/version.txt
index 7ee7020b38..7ec1d6db40 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-1.0.10
+2.1.0