code: def send(self, message_type, data, callback=None, one_way=False):
          
          message = validator_pb2.Message(
              correlation_id=_generate_id(),
              content=data,
              message_type=message_type)
  
          fut = future.Future(message.correlation_id, message.content,
                              callback, timeout=self._connection_timeout)
          if not one_way:
              self._futures.put(fut)
  
          self._send_receive_thread.send_message(message)
          return fut
docs: Sends a message of message_type
  
          Args:
              message_type (validator_pb2.Message): enum value
              data (bytes): serialized protobuf
              callback (function): a callback function to call when a
                  response to this message is received
  
          Returns:
              future.Future