@Test
public void testDefault() {

  String user;
  try {
    user = UserGroupInformation.getCurrentUser().getShortUserName();
  } catch (IOException e) {
    user = "hadoop";
  }
  Configuration conf = new Configuration(false);
  ugi.setConf(conf);
  Map<Integer, String> ids = ugi.ugiMap();
  assertEquals(2, ids.size());
  assertEquals(user, ids.get(0));
  assertEquals(user, ids.get(1));
}