code: def send_to_default_exchange(self, sess_id, message=None):
          
          msg = json.dumps(message, cls=ZEngineJSONEncoder)
          log.debug("Sending following message to %s queue through default exchange:\n%s" % (
              sess_id, msg))
          self.get_channel().publish(exchange='', routing_key=sess_id, body=msg)
docs: Send messages through RabbitMQ's default exchange,
          which will be delivered through routing_key (sess_id).
  
          This method only used for un-authenticated users, i.e. login process.
  
          Args:
              sess_id string: Session id
              message dict: Message object.