code: public void assignTransition(XEvent event, String transition) {
  		if (transition != null && transition.trim().length() > 0) {
  			XAttributeLiteral transAttr = (XAttributeLiteral) ATTR_TRANSITION
  					.clone();
  			transAttr.setValue(transition.trim());
  			event.getAttributes().put(KEY_TRANSITION, transAttr);
  		}
  	}
docs: Assigns a lifecycle transition string to the given event.
  
  @param event
  Event to be tagged.
  @param transition
  Lifecycle transition string to be assigned.