public static DefaultTreeModel getSingleColDefaultTreeModel(int level1, int level2, int level3, String label) {
List list = getList(10, label);
List list2 = new ArrayList();
for (int i =0 ,j = list.size(); i < j; i++)
list2.add(new DefaultTreeNode(list.get(i)));
return new DefaultTreeModel(new DefaultTreeNode(null, list2));
}