List<String> elvisGroups = groups.getGroups("elvis");
assertTrue(elvisGroups.contains("@lasVegas"));
// refresh cache - not testing this directly but if the results are ok
// after the refresh that means it worked fine (very likely)
groups.refresh();
// create an ACL with netgroups (@xxx)
acl = new AccessControlList("ja ratpack,@lasVegas");
// elvis is in @lasVegas
UserGroupInformation elvis =