protected Tree createTree() {
    final Tree tree = new Tree(new DefaultTreeModel(new DefaultMutableTreeNode()));

    tree.setCellRenderer(getTreeCellRenderer());
    tree.setRootVisible(false);
    tree.setShowsRootHandles(true);
    tree.addKeyListener(new TreeKeyListener());
    tree.addTreeSelectionListener(new MyTreeSelectionListener());

    if (!myAllowMultiSelection) {
      tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
    }

    new DoubleClickListener() {
      @Override
      protected boolean onDoubleClick(@NotNull MouseEvent e) {
        if (tree.getPathForLocation(e.getX(), e.getY()) != null) {
          doOKAction();
          return true;
        }
        return false;
      }
    }.installOn(tree);

    TreeUtil.installActions(tree);
    return tree;
  }
protected Tree createTree()