@Test
public void testGetPrincipalName() {

    assertEquals(AthenzUtils.getPrincipalName("domain", "service"), "domain.service");
    assertEquals(AthenzUtils.getPrincipalName("dDd", "SsS"), "ddd.sss");
    assertNull(AthenzUtils.getPrincipalName("domain", null));
    assertNull(AthenzUtils.getPrincipalName("domain", ""));
    assertNull(AthenzUtils.getPrincipalName(null, "service"));
    assertNull(AthenzUtils.getPrincipalName("", "service"));
}