code: def add_message(self, id, body, tags=False):
          
          if not tags:
              tags = {}
          try:
              self._tx_queue_lock.acquire()
              self._tx_queue.append(
                  EventHub_pb2.Message(id=id, body=body, tags=tags, zone_id=self.eventhub_client.zone_id))
          finally:
              self._tx_queue_lock.release()
          return self
docs: add messages to the rx_queue
          :param id: str message Id
          :param body: str the message body
          :param tags: dict[string->string] tags to be associated with the message
          :return: self