public void addListener(String eventName,mxIEventListener listener){
  if (eventListeners == null) {
    eventListeners=new ArrayList<Object>();
  }
  eventListeners.add(eventName);
  eventListeners.add(listener);
}

public void addListener ( String eventName , mxIEventListener listener ) { if ( eventListeners == null ) { eventListeners = new ArrayList < Object > ( ) ; } eventListeners . add ( eventName ) ; eventListeners . add ( listener ) ; }
binds the specified function to the given event name . if no event name is given , then the listener is registered for all events .
