private void walkTree(Consumer<? super CheckedTreeNode> consumer) {
    final TreeModel treeModel = myTree.getModel();
    final Object root = treeModel.getRoot();
    if (!(root instanceof CheckedTreeNode)) return;

    for (TreeNode node : TreeUtil.listChildren((CheckedTreeNode)root)) {
      if (!(node instanceof CheckedTreeNode)) continue;
      consumer.consume(((CheckedTreeNode)node));
    }
  }
private void walkTree(Consumer<? super CheckedTreeNode> consumer)