diff --git a/composer/workflows/airflow_db_cleanup.py b/composer/workflows/airflow_db_cleanup.py
index 45119168111..4fefdc99202 100644
--- a/composer/workflows/airflow_db_cleanup.py
+++ b/composer/workflows/airflow_db_cleanup.py
@@ -460,7 +460,7 @@ def cleanup_function(**context):
             dags = session.query(airflow_db_model.dag_id).distinct()
             session.commit()
 
-            list_dags = [str(list(dag)[0]) for dag in dags] + [None]
+            list_dags = [str(list(dag)[0]) for dag in dags]
             for dag_id in list_dags:
                 query = build_query(
                     session=session,
diff --git a/endpoints/bookstore-grpc-transcoding/api_config_auth.yaml b/endpoints/bookstore-grpc-transcoding/api_config_auth.yaml
index dfeaaf3264f..832be4e6d72 100644
--- a/endpoints/bookstore-grpc-transcoding/api_config_auth.yaml
+++ b/endpoints/bookstore-grpc-transcoding/api_config_auth.yaml
@@ -52,6 +52,12 @@ authentication:
     # Replace SERVICE-ACCOUNT-ID with your service account's email address.
     issuer: SERVICE-ACCOUNT-ID
     jwks_uri: https://www.googleapis.com/robot/v1/metadata/x509/SERVICE-ACCOUNT-ID
+    # Optional: if the JWTs you send (e.g. via jwt_token_gen.py's
+    # --audiences flag) use a custom "aud" claim instead of your Endpoints
+    # service name, uncomment this and set it to that same value, or ESP
+    # will reject the token with a JWT validation error. See
+    # https://cloud.google.com/endpoints/docs/grpc/troubleshoot-jwt
+    # audiences: YOUR-AUDIENCE-VALUE
   rules:
   # This auth rule will apply to all methods.
   - selector: "*"
diff --git a/endpoints/bookstore-grpc/api_config_auth.yaml b/endpoints/bookstore-grpc/api_config_auth.yaml
index dfeaaf3264f..832be4e6d72 100644
--- a/endpoints/bookstore-grpc/api_config_auth.yaml
+++ b/endpoints/bookstore-grpc/api_config_auth.yaml
@@ -52,6 +52,12 @@ authentication:
     # Replace SERVICE-ACCOUNT-ID with your service account's email address.
     issuer: SERVICE-ACCOUNT-ID
     jwks_uri: https://www.googleapis.com/robot/v1/metadata/x509/SERVICE-ACCOUNT-ID
+    # Optional: if the JWTs you send (e.g. via jwt_token_gen.py's
+    # --audiences flag) use a custom "aud" claim instead of your Endpoints
+    # service name, uncomment this and set it to that same value, or ESP
+    # will reject the token with a JWT validation error. See
+    # https://cloud.google.com/endpoints/docs/grpc/troubleshoot-jwt
+    # audiences: YOUR-AUDIENCE-VALUE
   rules:
   # This auth rule will apply to all methods.
   - selector: "*"
diff --git a/texttospeech/snippets/streaming_tts_quickstart.py b/texttospeech/snippets/streaming_tts_quickstart.py
index 90c65063e94..4a52b4f16b9 100644
--- a/texttospeech/snippets/streaming_tts_quickstart.py
+++ b/texttospeech/snippets/streaming_tts_quickstart.py
@@ -58,8 +58,19 @@ def request_generator():
 
     streaming_responses = client.streaming_synthesize(request_generator())
 
-    for response in streaming_responses:
-        print(f"Audio content size in bytes is: {len(response.audio_content)}")
+    # The response stream contains headerless linear PCM (LINEAR16) audio
+    # sampled at 24000 Hz. Write it to a standard playable .wav file by
+    # adding a proper WAV header with the stdlib `wave` module, rather than
+    # a hand-rolled byte header.
+    import wave
+
+    with wave.open("streaming_tts_quickstart_output.wav", "wb") as wav_file:
+        wav_file.setnchannels(1)  # LINEAR16 audio from this API is mono.
+        wav_file.setsampwidth(2)  # 16-bit samples (LINEAR16) = 2 bytes/sample.
+        wav_file.setframerate(24000)  # Sample rate used above.
+        for response in streaming_responses:
+            print(f"Audio content size in bytes is: {len(response.audio_content)}")
+            wav_file.writeframes(response.audio_content)
     # [END tts_synthezise_streaming]