def on_message(self, unused_channel, basic_deliver, properties, body):
_logger.debug('<STR_LIT>',<EOL>basic_deliver.delivery_tag, properties.app_id, body)<EOL>if self.ws and body:<EOL><INDENT>self.messages.append(body)<EOL><DEDENT>_logger.debug('<STR_LIT>', len(self.ws))<EOL>_logger.debug('<STR_LIT>', len(self.messages))<EOL>self.acknowledge_message(basic_deliver.delivery_tag)<EOL>
Invoked by pika when a message is delivered from RabbitMQ. The
        channel is passed for your convenience. The basic_deliver object that
        is passed in carries the exchange, routing key, delivery tag and
        a redelivered flag for the message. The properties passed in is an
        instance of BasicProperties with the message properties and the body
        is the message that was sent.

        :param pika.channel.Channel unused_channel: The channel object
        :param pika.Spec.Basic.Deliver: basic_deliver method
        :param pika.Spec.BasicProperties: properties
        :param str|unicode body: The message body