code: def strip_doc_string(proto):  # type: (google.protobuf.message.Message) -> None
      
      assert isinstance(proto, google.protobuf.message.Message)
      for descriptor in proto.DESCRIPTOR.fields:
          if descriptor.name == 'doc_string':
              proto.ClearField(descriptor.name)
          elif descriptor.type == descriptor.TYPE_MESSAGE:
              if descriptor.label == descriptor.LABEL_REPEATED:
                  for x in getattr(proto, descriptor.name):
                      strip_doc_string(x)
              elif proto.HasField(descriptor.name):
                  strip_doc_string(getattr(proto, descriptor.name))
docs: Empties `doc_string` field on any nested protobuf messages