code: def on_channel_closed(self, channel, reply_code, reply_text):
          
          self._logger.warning('Channel was closed: (%s) %s', reply_code, reply_text)
          if not self._closing:
              self.close_connection()
docs: Invoked by pika when RabbitMQ unexpectedly closes the channel.
          Channels are usually closed if you attempt to do something that
          violates the protocol, such as re-declare an exchange or queue with
          different parameters. In this case, we'll close the connection
          to shutdown the object.
  
          :param pika.channel.Channel: The closed channel
          :param int reply_code: The numeric reason the channel was closed
          :param str reply_text: The text reason the channel was closed