private TreeModel createTreeModel() {
private DefaultTreeModel createTreeModel() {
  private TreeModel createTreeModel() {    final DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");    final DefaultMutableTreeNode child1 = new DefaultMutableTreeNode("Child1");    final DefaultMutableTreeNode child2 = new DefaultMutableTreeNode("Child2");    final DefaultMutableTreeNode grandChild =      new DefaultMutableTreeNode("Grandchild");    child1.add(grandChild);    root.add(child1);    root.add(child2);    return new DefaultTreeModel(root);  }