DefaultMutableTreeNode c1 = new DefaultMutableTreeNode("c1");
c2 = new DefaultMutableTreeNode("c2");
c3 = new DefaultMutableTreeNode("c3");
DefaultMutableTreeNode cc2 = new DefaultMutableTreeNode("cc2");
DefaultTreeModel model = new DefaultTreeModel(root);
model.insertNodeInto(c1, root, 0);
model.insertNodeInto(c2, root, 1);
model.insertNodeInto(cc2, c2, 0);
model.insertNodeInto(c3, root, 2);
return model;
}