@Override
    public List<Acl.User> getAvailableAclUsers() {
        return new ArrayList<>(Arrays.asList(
                new Acl.CanonicalUser(),
                new Acl.GroupUser(Acl.GroupUser.AUTHENTICATED, false) {
                    @Override
                    public String getPlaceholder() {
                        return LocaleFactory.localizedString("http://acs.amazonaws.com/groups/global/AuthenticatedUsers", "S3");
                    }
                },
                new Acl.GroupUser(Acl.GroupUser.EVERYONE, false),
                new Acl.EmailUser() {
                    @Override
                    public String getPlaceholder() {
                        return LocaleFactory.localizedString("Amazon Customer Email Address", "S3");
                    }
                })
        );
    }
@Test
    public void testRoles() {
        final S3AccessControlListFeature f = new S3AccessControlListFeature(session);
        assertTrue(f.getAvailableAclUsers().stream().filter(user -> user instanceof Acl.CanonicalUser).findAny().isPresent());
        assertTrue(f.getAvailableAclUsers().stream().filter(user -> user instanceof Acl.EmailUser).findAny().isPresent());
    }