}
});
menu.add(follow);
menu.add(unfollow);
tree.setContextMenu(menu);
tree.addBeforeShowContextMenuHandler(new BeforeShowContextMenuHandler() {
public void onBeforeShowContextMenu(BeforeShowContextMenuEvent event) {
GroupJobTreeModel model=tree.getSelectionModel().getSelectedItem();
if(model!=null){
if(model.isFollow()){
follow.hide();