code: def publish_message(self, message, expire=None):
          
          if expire is None:
              expire = self._expire
          if not isinstance(message, RedisMessage):
              raise ValueError('message object is not of type RedisMessage')
          for channel in self._publishers:
              self._connection.publish(channel, message)
              if expire > 0:
                  self._connection.setex(channel, expire, message)
docs: Publish a ``message`` on the subscribed channel on the Redis datastore.
          ``expire`` sets the time in seconds, on how long the message shall additionally of being
          published, also be persisted in the Redis datastore. If unset, it defaults to the
          configuration settings ``WS4REDIS_EXPIRE``.