Implement a test against Showcase returning metadata as bytes
Update showcase to test metadata with bytes and add a unit test to confirm this behaviour.
This is an issue with the Showcase server not returning the metadata? Then we should file an issue in gapic-showcase to provide that functionality, restrict this issue to be testing that functionality in the generator, and make this issue dependent on that one.
When filing the issue on Showcase, could you be more specific about that is missing: what service and RPC under which conditions does not return metadata?
This would require changing Showcase so that when the metadata key as a suffix -bin, it returns data of type bytes. Ref
We should still file the necessary issue in the Showcase repo.