@Test
 public void testHasChildren() {
   System.out.println("testHasChildren");
   for (Category root : serviceStub.getRootCategories()) {
     assertTrue(container.hasChildren(root.getId()));
     for (Category c : serviceStub.getChildren(root)) {
       assertFalse(container.hasChildren(c.getId()));
     }
   }
 }
 @Test
 public void testHasChildren_Nonexistent() {
   System.out.println("testHasChildren_Nonexistent");
   assertFalse(container.hasChildren(-123l));
 }