MixedTreeModel model = new MixedTreeModel();
DefaultMutableTreeNode tree = new DefaultMutableTreeNode("D_0");
tree.add(new DefaultMutableTreeNode("D_0_0"));
tree.add(new DefaultMutableTreeNode("D_0_1"));
UITreeData data = new UITreeData();
data.setValue(tree);
UITreeNode node = new UITreeNode();
// model.beginBuildNodeData(data);
model.beginBuildNode(node);
model.beginBuildNode(node);