public void processContainerEvent(ContainerEvent event) {
   if (cntrListener != null) {
     switch (event.getID()) {
       case ContainerEvent.COMPONENT_ADDED:
         cntrListener.componentAdded(event);
         break;
       case ContainerEvent.COMPONENT_REMOVED:
         cntrListener.componentRemoved(event);
         break;
     }
   }
 }
 /**
  * Handles the componentRemoved container event by invoking the componentRemoved methods on
  * listener-a and listener-b.
  *
  * @param e the component event
  */
 public void componentRemoved(ContainerEvent e) {
   ((ContainerListener) a).componentRemoved(e);
   ((ContainerListener) b).componentRemoved(e);
 }