/** test constructor */
  @Test
  public void testConstructor() throws Exception {
    UserGroupInformation ugi =
        UserGroupInformation.createUserForTesting("user2/[email protected]", GROUP_NAMES);
    // make sure the short and full user names are correct
    assertEquals("user2/[email protected]", ugi.getUserName());
    assertEquals("user2", ugi.getShortUserName());
    ugi = UserGroupInformation.createUserForTesting(USER_NAME, GROUP_NAMES);
    assertEquals("user1", ugi.getShortUserName());

    // failure test
    testConstructorFailures(null);
    testConstructorFailures("");
  }
 @Test
 public void testGettingGroups() throws Exception {
   UserGroupInformation uugi = UserGroupInformation.createUserForTesting(USER_NAME, GROUP_NAMES);
   assertEquals(USER_NAME, uugi.getUserName());
   assertArrayEquals(new String[] {GROUP1_NAME, GROUP2_NAME, GROUP3_NAME}, uugi.getGroupNames());
 }