code: def _send_unary_request(self, request):
          
          if request.ack_ids:
              self._client.acknowledge(
                  subscription=self._subscription, ack_ids=list(request.ack_ids)
              )
  
          if request.modify_deadline_ack_ids:
              # Send ack_ids with the same deadline seconds together.
              deadline_to_ack_ids = collections.defaultdict(list)
  
              for n, ack_id in enumerate(request.modify_deadline_ack_ids):
                  deadline = request.modify_deadline_seconds[n]
                  deadline_to_ack_ids[deadline].append(ack_id)
  
              for deadline, ack_ids in six.iteritems(deadline_to_ack_ids):
                  self._client.modify_ack_deadline(
                      subscription=self._subscription,
                      ack_ids=ack_ids,
                      ack_deadline_seconds=deadline,
                  )
  
          _LOGGER.debug("Sent request(s) over unary RPC.")
docs: Send a request using a separate unary request instead of over the
          stream.
  
          Args:
              request (types.StreamingPullRequest): The stream request to be
                  mapped into unary requests.