code: def __str__(self):
      return (
          f"MQChannel(host={self._host}, port={self._port}, namespace={self._namespace}, "
          f"src_party_id={self._src_party_id}, src_role={self._src_role}，"
          f"dst_party_id={self._dst_party_id}, dst_role={self._dst_role}，"
          f"send_queue_name={self._send_queue_name}, receive_queue_name={self._receive_queue_name})，"
      )
  
file_path: FATE/python/fate/arch/federation/backends/rabbitmq/_mq_channel.py
imports: import json
  import logging
  import pika
  from fate.arch.federation.message_queue import nretry
label_desc: Use image node_id 2 for calling the MQChannel obj's underlying member method code with example usage: obj.__str__() and returns: str, self, str, self, str, self, str, self, str, self, str, self, str, self, str, self, str, self, str