[hardwired]

Code:

    public TreePopup() {
        popup = new JPopupMenu();
        popup.setInvoker(tree);
        PopupHandler handler = new PopupHandler(tree, popup);
        JMenu menu = new JMenu("insert");
        popup.add(menu);
        menu.add(getMenuItem("add child",   handler));
        menu.add(getMenuItem("add sibling", handler));
    }