@Override
 public void addNotify() {
   super.addNotify();
   if (nodeChangeListener == null) {
     nodeChangeListener = new NodeChangeListener();
   }
   manager.addPropertyChangeListener(nodeChangeListener);
   manager.setRootContext(getRootContext());
   treeView.expandAll();
 }
 @Override
 public void removeNotify() {
   manager.removePropertyChangeListener(nodeChangeListener);
   super.removeNotify();
 }