are google.protobuf and google.protobuf.pyext supposed to be namespace packages? #5194

I'm trying to understand why 786f80f added the namespace package stanza to google/protobuf/__init__.py and google/protobuf/pyext/__init__.py. I see the google namespace has a fraught history, but is it actually expected that other packages will put code in google.protobuf or google.protobuf.pyext? Note also google/protobuf/__init__.py technically violates the requirement that a namespace packages's __init__.py must not include any other code and data aside from the namespace declaration.

I think either the namespace declaration code should be removed from google/protobuf/__init__.py and google/protobuf/pyext/__init__.py, or these namespace packages should be declared along with the google namespace in setup.py.