使用mvvm时，从Zk中的嵌套类向父类发送通知

class A{
  private List<B> list;
  // getter setter
  public class B{
    @command
    public void delete(){
       // remove itself from list
       // Now how to post event to event queue to update list on browser
    }  
  }
}
class A{
  private List<B> list;
  // getter se