code: def on_channel_open(self, channel):
          
          logger.debug('Channel opened')
          self._channel = channel
          self.add_on_channel_close_callback()
          self.setup_qos()
docs: Called by pika when the channel has been opened.
  
          The channel object is passed in so we can make use of it. Since the
          channel is now open, we'll start consuming.
  
          :param pika.channel.Channel channel: The channel object