code: public JsTopicMessageController getJsTopicMessageController(String topic) {
  		logger.debug("Looking for messageController for topic '{}'", topic);
  		JsTopicMessageController messageController = messageControllerCache.loadFromCache(topic);
  		if(null == messageController) { // not in cache
  			messageController = getJsTopicMessageControllerFromJsTopicControl(topic); // get from JsTopicControl
  			if(null == messageController) {
  				messageController = getJsTopicMessageControllerFromJsTopicControls(topic); // get from JsTopicControls
  				if(null == messageController) {
  					messageController = new DefaultJsTopicMessageController();
  				}
  			}
  			messageControllerCache.saveToCache(topic, messageController.getClass()); // save in cache
  		}
  		return messageController;
  	}
docs: Get jstopic message controller
  @param topic
  @return