@Test
public void testFragment() {

  Tokens.Fragment fragment = Tokens.fragment("foo", 1);
  assertEquals("foo", fragment.toString());
  assertFragment(1, "foo", fragment);
  ObjectTester.assertEqual(fragment, fragment, Tokens.fragment("foo", 1));
  ObjectTester.assertNotEqual(fragment,
      Tokens.fragment("foo", 2), Tokens.fragment("foo", "1"), Tokens.fragment("bar", 1),
      "foo", 1);
}