@Override
    public Object nextElement() {
      Enumeration e = myStack.peek();
      Object node = e.nextElement();
      if (!e.hasMoreElements()) {
        myStack.pop();
      }
      Enumeration children = new ChildrenEnumeration(myTreeModel, node);
      if (children.hasMoreElements()) {
        myStack.push(children);
      }
      return node;
    }
@Override
    public Object nextElement()