code: def _basic_return(self, frame_in):
          
          reply_text = try_utf8_decode(frame_in.reply_text)
          message = (
              "Message not delivered: %s (%s) to queue '%s' from exchange '%s'" %
              (
                  reply_text,
                  frame_in.reply_code,
                  frame_in.routing_key,
                  frame_in.exchange
              )
          )
          exception = AMQPMessageError(message,
                                       reply_code=frame_in.reply_code)
          self.exceptions.append(exception)
docs: Handle a Basic Return Frame and treat it as an error.
  
          :param specification.Basic.Return frame_in: Amqp frame.
  
          :return: