private void initTree(final Tree tree) {
    final TreeCellRenderer rootsTreeCellRenderer = new MigrationRootsTreeCellRenderer();
    tree.setCellRenderer(rootsTreeCellRenderer);
    tree.setRootVisible(false);
    tree.setShowsRootHandles(true);

    TreeUtil.installActions(tree);
    TreeUtil.expandAll(tree);
    SmartExpander.installOn(tree);
    EditSourceOnDoubleClickHandler.install(tree);
    TreeUIHelper.getInstance().installTreeSpeedSearch(tree);
    PopupHandler.installPopupMenu(tree, createTreePopupActions(), "MigrationPanelPopup");
  }
private void initTree(final Tree tree)