private void notifies() {
   for (Iterator i = listeners.iterator(); i.hasNext(); ) {
     ConfigurationListener l = (ConfigurationListener) i.next();
     l.notifyChanges();
   }
 }
 private void triggerEvent(int type) {
   ConfigurationEvent evt = new ConfigurationEvent(type);
   for (ConfigurationListener listener : listeners) {
     listener.configurationEvent(evt);
   }
 }