async def intercept_stream_stream(self, continuation, client_call_details,
                                   request_iterator):
     self.request_iterator = CountingRequestIterator(request_iterator)
     call = await continuation(client_call_details, self.request_iterator)
     self.response_iterator = CountingResponseIterator(call)
     return self.response_iterator
 async def intercept_stream_unary(self, continuation, client_call_details,
                                  request_iterator):
     self.request_iterator = CountingRequestIterator(request_iterator)
     call = await continuation(client_call_details, self.request_iterator)
     return call