@Test
public void testGetUniqueIdByMemberPatternWhenMembershipAttributeIsNull() {

  // GIVEN
  Configuration configuration = createNiceMock(Configuration.class);
  Users users = createNiceMock(Users.class);
  String  syncUserMemberPattern = "(?<sid>.*);(?<guid>.*);(?<member>.*)";
  AmbariLdapDataPopulatorTestInstance populator = new AmbariLdapDataPopulatorTestInstance(configuration, users);
  // WHEN
  String result = populator.getUniqueIdByMemberPattern(null, syncUserMemberPattern);
  // THEN
  assertNull(result);
}