diff --git a/src/main/java/walkingkooka/j2cl/maven/J2clArtifact.java b/src/main/java/walkingkooka/j2cl/maven/J2clArtifact.java
index e9bebf22..46b54e7e 100644
--- a/src/main/java/walkingkooka/j2cl/maven/J2clArtifact.java
+++ b/src/main/java/walkingkooka/j2cl/maven/J2clArtifact.java
@@ -29,6 +29,7 @@
 import walkingkooka.collect.list.Lists;
 import walkingkooka.collect.map.Maps;
 import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.log.TreeLogger;
 import walkingkooka.predicate.Predicates;
 import walkingkooka.reflect.PackageName;
@@ -566,7 +567,7 @@ private void verify(final TreeLogger logger) {
         this.context.verifyClasspathRequiredJavascriptSourceRequiredIgnoredDependencies(
                 all.stream()
                         .map(J2clArtifact::coords)
-                        .collect(Collectors.toCollection(Sets::sorted)),
+                        .collect(Collectors.toCollection(SortedSets::tree)),
                 this,
                 logger
         );
@@ -708,7 +709,7 @@ private void logDependencies(final String label,
                 this.dependencies().stream()
                         .filter(filter)
                         .map(J2clArtifact::toString)
-                        .collect(Collectors.toCollection(Sets::sorted))
+                        .collect(Collectors.toCollection(SortedSets::tree))
         );
     }
 
diff --git a/src/main/java/walkingkooka/j2cl/maven/J2clArtifactCoords.java b/src/main/java/walkingkooka/j2cl/maven/J2clArtifactCoords.java
index 2bb07a68..a563cf44 100644
--- a/src/main/java/walkingkooka/j2cl/maven/J2clArtifactCoords.java
+++ b/src/main/java/walkingkooka/j2cl/maven/J2clArtifactCoords.java
@@ -21,7 +21,7 @@
 import org.apache.maven.artifact.DefaultArtifact;
 import org.apache.maven.artifact.handler.ArtifactHandler;
 import org.apache.maven.model.Dependency;
-import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.unpack.J2clTaskUnpack;
 import walkingkooka.text.CharSequences;
 
@@ -40,7 +40,7 @@ final class J2clArtifactCoords implements Comparable<J2clArtifactCoords> {
      * Creates a sorted {@link Set} to hold coords.
      */
     static Set<J2clArtifactCoords> set() {
-        return Sets.sorted();
+        return SortedSets.tree();
     }
 
     /**
diff --git a/src/main/java/walkingkooka/j2cl/maven/J2clMavenContext.java b/src/main/java/walkingkooka/j2cl/maven/J2clMavenContext.java
index 97d672d0..55e1d953 100644
--- a/src/main/java/walkingkooka/j2cl/maven/J2clMavenContext.java
+++ b/src/main/java/walkingkooka/j2cl/maven/J2clMavenContext.java
@@ -22,7 +22,7 @@
 import walkingkooka.Context;
 import walkingkooka.collect.list.Lists;
 import walkingkooka.collect.map.Maps;
-import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.closure.ClosureFormattingOption;
 import walkingkooka.j2cl.maven.hash.HashBuilder;
 import walkingkooka.j2cl.maven.log.MavenLogger;
@@ -307,7 +307,7 @@ private void prepareTasks(final J2clArtifact artifact) {
         if (false == this.tasks.containsKey(artifact)) {
 
             // keep transitive dependencies alphabetical sorted for better readability when trySubmitTasks pretty prints queue processing.
-            final Set<J2clArtifact> required = Sets.sorted();
+            final Set<J2clArtifact> required = SortedSets.tree();
 
             this.tasks.put(artifact, required);
 
diff --git a/src/main/java/walkingkooka/j2cl/maven/J2clMojoBuildTestWatch.java b/src/main/java/walkingkooka/j2cl/maven/J2clMojoBuildTestWatch.java
index b46fc1bc..7f2f1537 100644
--- a/src/main/java/walkingkooka/j2cl/maven/J2clMojoBuildTestWatch.java
+++ b/src/main/java/walkingkooka/j2cl/maven/J2clMojoBuildTestWatch.java
@@ -29,7 +29,7 @@
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
 import org.eclipse.aether.repository.RemoteRepository;
-import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.closure.ClosureFormattingOption;
 import walkingkooka.j2cl.maven.log.TreeLogger;
 import walkingkooka.text.CharSequences;
@@ -222,7 +222,7 @@ final Set<ClosureFormattingOption> formatting() {
     final Set<String> javaCompilerArguments() {
         return this.javaCompilerArguments.stream()
                 .map(String::trim)
-                .collect(Collectors.toCollection(Sets::sorted));
+                .collect(Collectors.toCollection(SortedSets::tree));
     }
 
     @SuppressWarnings("MismatchedQueryAndUpdateOfCollection")
diff --git a/src/main/java/walkingkooka/j2cl/maven/J2clMojoTest.java b/src/main/java/walkingkooka/j2cl/maven/J2clMojoTest.java
index f5fc9368..d5237db8 100644
--- a/src/main/java/walkingkooka/j2cl/maven/J2clMojoTest.java
+++ b/src/main/java/walkingkooka/j2cl/maven/J2clMojoTest.java
@@ -23,7 +23,7 @@
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.plugins.annotations.ResolutionScope;
 import walkingkooka.collect.list.Lists;
-import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.log.BrowserLogLevel;
 import walkingkooka.j2cl.maven.log.MavenLogger;
 import walkingkooka.j2cl.maven.log.TreeLogger;
@@ -147,7 +147,7 @@ private List<String> findTestClassNames(final TreeLogger logger) throws IOExcept
                 logger.line(testSourceRootPath.toAbsolutePath().toString());
                 logger.indent();
                 {
-                    final Set<String> tests = Sets.sorted();
+                    final Set<String> tests = SortedSets.tree();
                     final List<PathMatcher> pathMatchers = this.tests(testSourceRootPath);
 
                     Files.walkFileTree(testSourceRootPath, new SimpleFileVisitor<>() {
diff --git a/src/main/java/walkingkooka/j2cl/maven/J2clPath.java b/src/main/java/walkingkooka/j2cl/maven/J2clPath.java
index d78e2a57..a47ffe58 100644
--- a/src/main/java/walkingkooka/j2cl/maven/J2clPath.java
+++ b/src/main/java/walkingkooka/j2cl/maven/J2clPath.java
@@ -21,6 +21,7 @@
 import walkingkooka.collect.list.Lists;
 import walkingkooka.collect.map.Maps;
 import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.file.Files2;
 import walkingkooka.j2cl.maven.log.TreeFormat;
 import walkingkooka.j2cl.maven.log.TreeLogger;
@@ -273,7 +274,7 @@ public Set<J2clPath> gatherFiles(final Predicate<Path> filter) throws IOExceptio
         return Files.find(this.path(), Integer.MAX_VALUE, (p, a) -> filter.test(p))
                 .map(J2clPath::with)
                 .sorted()
-                .collect(Collectors.toCollection(Sets::sorted));
+                .collect(Collectors.toCollection(SortedSets::tree));
     }
 
     public boolean isFile() {
diff --git a/src/main/java/walkingkooka/j2cl/maven/closure/ClosureCompiler.java b/src/main/java/walkingkooka/j2cl/maven/closure/ClosureCompiler.java
index fa151223..0223119e 100644
--- a/src/main/java/walkingkooka/j2cl/maven/closure/ClosureCompiler.java
+++ b/src/main/java/walkingkooka/j2cl/maven/closure/ClosureCompiler.java
@@ -26,6 +26,7 @@
 import walkingkooka.collect.list.Lists;
 import walkingkooka.collect.map.Maps;
 import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.J2clArtifact;
 import walkingkooka.j2cl.maven.J2clMavenContext;
 import walkingkooka.j2cl.maven.J2clPath;
@@ -163,7 +164,9 @@ private static boolean compile0(final J2clArtifact artifact,
                     defines,
                     entryPoints,
                     externs,
-                    formatting.stream().map(ClosureFormattingOption::name).collect(Collectors.toCollection(Sets::sorted)),
+                    formatting.stream()
+                            .map(ClosureFormattingOption::name)
+                            .collect(Collectors.toCollection(SortedSets::tree)),
                     languageOut,
                     sourceMaps,
                     unitedSourceRoot,
@@ -250,7 +253,7 @@ private static Map<String, Collection<String>> prepareArguments(final Compilatio
 
             arguments.put("--compilation_level", Sets.of(compilationLevel.name()));
             {
-                final Set<String> definesSet = Sets.sorted();
+                final Set<String> definesSet = SortedSets.tree();
                 if (compilationLevel == CompilationLevel.BUNDLE) {
                     definesSet.add("goog.ENABLE_DEBUG_LOADER=false");
                 }
diff --git a/src/main/java/walkingkooka/j2cl/maven/hash/J2clTaskHash.java b/src/main/java/walkingkooka/j2cl/maven/hash/J2clTaskHash.java
index ae15c111..206dfb48 100644
--- a/src/main/java/walkingkooka/j2cl/maven/hash/J2clTaskHash.java
+++ b/src/main/java/walkingkooka/j2cl/maven/hash/J2clTaskHash.java
@@ -18,7 +18,7 @@
 package walkingkooka.j2cl.maven.hash;
 
 import com.google.common.collect.Lists;
-import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.J2clArtifact;
 import walkingkooka.j2cl.maven.J2clMavenContext;
 import walkingkooka.j2cl.maven.J2clPath;
@@ -69,7 +69,7 @@ public J2clTaskResult execute(final J2clArtifact artifact,
                                   final J2clTaskKind kind,
                                   final C context,
                                   final TreeLogger logger) throws Exception {
-        final Set<String> hashItemNames = Sets.sorted();
+        final Set<String> hashItemNames = SortedSets.tree();
         final HashBuilder hash = HashBuilder.empty();
         context.computeHash(
                 artifact,
diff --git a/src/main/java/walkingkooka/j2cl/maven/output/J2clTaskOutputAssembler.java b/src/main/java/walkingkooka/j2cl/maven/output/J2clTaskOutputAssembler.java
index b58cbad1..cf553a73 100644
--- a/src/main/java/walkingkooka/j2cl/maven/output/J2clTaskOutputAssembler.java
+++ b/src/main/java/walkingkooka/j2cl/maven/output/J2clTaskOutputAssembler.java
@@ -18,6 +18,7 @@
 package walkingkooka.j2cl.maven.output;
 
 import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.J2clArtifact;
 import walkingkooka.j2cl.maven.J2clMavenContext;
 import walkingkooka.j2cl.maven.J2clPath;
@@ -121,7 +122,7 @@ public J2clTaskResult executeWithDirectory(final J2clArtifact artifact,
         }
         logger.outdent();
 
-        final Set<J2clPath> destinationFiles = Sets.sorted();
+        final Set<J2clPath> destinationFiles = SortedSets.tree();
         destinationFiles.addAll(closureCompileDestinationFiles);
         destinationFiles.addAll(unpackPublicDestinationFiles);
 
diff --git a/src/main/java/walkingkooka/j2cl/maven/shade/J2clTaskShade.java b/src/main/java/walkingkooka/j2cl/maven/shade/J2clTaskShade.java
index 00d885f0..463d6dc6 100644
--- a/src/main/java/walkingkooka/j2cl/maven/shade/J2clTaskShade.java
+++ b/src/main/java/walkingkooka/j2cl/maven/shade/J2clTaskShade.java
@@ -17,7 +17,7 @@
 
 package walkingkooka.j2cl.maven.shade;
 
-import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.J2clArtifact;
 import walkingkooka.j2cl.maven.J2clMavenContext;
 import walkingkooka.j2cl.maven.J2clPath;
@@ -117,10 +117,10 @@ private void copyAndShade(final J2clArtifact artifact,
 
         final Set<J2clPath> files = root.gatherFiles(J2clPath.ALL_FILES.and(filter));
 
-        final Set<J2clPath> possibleFiles = Sets.sorted();
+        final Set<J2clPath> possibleFiles = SortedSets.tree();
         possibleFiles.addAll(files);
 
-        final Set<J2clPath> nonShadedFiles = Sets.sorted();
+        final Set<J2clPath> nonShadedFiles = SortedSets.tree();
         nonShadedFiles.addAll(files);
 
         for (final Entry<PackageName, PackageName> mapping : shade.entrySet()) {
@@ -131,7 +131,7 @@ private void copyAndShade(final J2clArtifact artifact,
                     output :
                     output.append(replace.replace('.', File.separatorChar));
 
-            final Set<J2clPath> shadedFiles = Sets.sorted();
+            final Set<J2clPath> shadedFiles = SortedSets.tree();
             final J2clPath shadedRoot = root.append(find.replace('.', File.separatorChar));
 
             // filter only files belonging to and under shade source root
diff --git a/src/main/java/walkingkooka/j2cl/maven/strip/GwtIncompatibleStripPreprocessor.java b/src/main/java/walkingkooka/j2cl/maven/strip/GwtIncompatibleStripPreprocessor.java
index f89a8afc..9fc0251d 100644
--- a/src/main/java/walkingkooka/j2cl/maven/strip/GwtIncompatibleStripPreprocessor.java
+++ b/src/main/java/walkingkooka/j2cl/maven/strip/GwtIncompatibleStripPreprocessor.java
@@ -22,6 +22,7 @@
 import com.google.j2cl.tools.gwtincompatible.GwtIncompatibleStripper;
 import walkingkooka.collect.list.Lists;
 import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.j2cl.maven.J2clPath;
 import walkingkooka.j2cl.maven.J2clTaskResult;
 import walkingkooka.j2cl.maven.log.TreeFormat;
@@ -215,7 +216,7 @@ private static Set<J2clPath> gatherFiles(final J2clPath root,
 
     private static Set<J2clPath> gatherFiles0(final J2clPath root,
                                               final Predicate<Path> include) throws IOException {
-        final SortedSet<J2clPath> files = Sets.sorted();
+        final SortedSet<J2clPath> files = SortedSets.tree();
 
         Files.walkFileTree(
                 root.path(),
diff --git a/src/test/java/walkingkooka/j2cl/maven/J2clArtifactGraphCalculatorTest.java b/src/test/java/walkingkooka/j2cl/maven/J2clArtifactGraphCalculatorTest.java
index 8a1ea07a..1cda58bd 100644
--- a/src/test/java/walkingkooka/j2cl/maven/J2clArtifactGraphCalculatorTest.java
+++ b/src/test/java/walkingkooka/j2cl/maven/J2clArtifactGraphCalculatorTest.java
@@ -20,6 +20,7 @@
 import org.junit.jupiter.api.Test;
 import walkingkooka.collect.map.Maps;
 import walkingkooka.collect.set.Sets;
+import walkingkooka.collect.set.SortedSets;
 import walkingkooka.reflect.ClassTesting2;
 import walkingkooka.reflect.JavaVisibility;
 
@@ -170,7 +171,7 @@ private Map<J2clArtifactCoords, Set<J2clArtifactCoords>> transform(final Map<Str
     private Set<J2clArtifactCoords> transformCsv(final String csv) {
         return Arrays.stream(csv.isEmpty() ? new String[0] : csv.split(","))
                 .map(J2clArtifactCoords::parse)
-                .collect(Collectors.toCollection(Sets::sorted));
+                .collect(Collectors.toCollection(SortedSets::tree));
     }
 
     private void runAndCheck0(final Map<J2clArtifactCoords, Set<J2clArtifactCoords>> flat,