private DefaultMutableTreeNode findNode(@NotNull JTree tree, boolean forward) {
    TreePath selectionPath = tree.getSelectionPath();
    TreeNode selectedNode = null;
    if (selectionPath != null) {
      selectedNode = (TreeNode)selectionPath.getLastPathComponent();
    }
    return findNextNodeAfter(tree, selectedNode, forward);
  }
private DefaultMutableTreeNode findNode(@NotNull JTree tree, boolean forward)