Simpler repro of problem

.github/trigger_files/beam_PostCommit_Python.json

@@ -1,5 +1,5 @@
 {
   "comment": "Modify this file in a trivial way to cause this test suite to run.",
-  "modification": 2
+  "modification": 1
 }
 

.github/trigger_files/beam_PostCommit_Python_ValidatesContainer_Dataflow.json

@@ -1,4 +1,3 @@
 {
-    "comment": "Modify this file in a trivial way to cause this test suite to run",
-    "modification": "1"
+    "comment": "Modify this file in a trivial way to cause this test suite to run"
 }

sdks/python/apache_beam/io/gcp/bigquery_write_it_test.py

@@ -491,7 +491,6 @@ def test_big_query_write_insert_non_transient_api_call_error(self):
       # pylint: disable=expression-not-assigned
       errors = (
           p | 'create' >> beam.Create(input_data)
-          | beam.WindowInto(beam.transforms.window.FixedWindows(10))
           | 'write' >> beam.io.WriteToBigQuery(
               table_id,
               schema=table_schema,

sdks/python/apache_beam/utils/windowed_value_test.py

@@ -27,6 +27,7 @@
 from parameterized import parameterized
 from parameterized import parameterized_class
 
+import apache_beam as beam
 from apache_beam.utils import windowed_value
 from apache_beam.utils.timestamp import Timestamp
 
@@ -75,6 +76,21 @@ def test_pickle(self):
     wv = windowed_value.WindowedValue(1, 3, (), pane_info)
     self.assertTrue(pickle.loads(pickle.dumps(wv)) == wv)
 
+  def test_encoding_global_window_in_interval_window(self):
+    input_data = ['123']
+
+    class ComputeWordLengthFn(beam.DoFn):
+      def process(self, element):
+        pass
+
+      def finish_bundle(self):
+        yield beam.transforms.window.GlobalWindows.windowed_value('test')
+
+    with beam.Pipeline() as p:
+      (p | 'create' >> beam.Create(input_data)
+      | beam.WindowInto(beam.transforms.window.FixedWindows(10))
+      | beam.ParDo(ComputeWordLengthFn()))
+
 
 WINDOWED_BATCH_INSTANCES = [
     windowed_value.HomogeneousWindowedBatch.of(