// Test with empty groups
        testUser.setGroupNames(new String[] {});
        assertNotNull(fessUserBean.getGroups());
        assertEquals(0, fessUserBean.getGroups().length);

        // Test with single group
        testUser.setGroupNames(new String[] { "developers" });
        String[] groups = fessUserBean.getGroups();
        assertEquals(1, groups.length);
        assertEquals("developers", groups[0]);

            if (StringUtil.isEmpty(key) || userBean
                    .map(user -> stream(user.getRoles()).get(stream -> stream.anyMatch(s -> (ROLE_VALUE_PREFIX + s).equals(key)))
                            || stream(user.getGroups()).get(stream -> stream.anyMatch(s -> (GROUP_VALUE_PREFIX + s).equals(key))))
                    .orElse(false)) {
                return p.getSecond();
            }
            return null;

        User user = new User();
        user.setName(username);
        user.setPassword(password);
        user.setRoles(new String[] { "role1", "role2" });
        user.setGroups(new String[] { "group1", "group2" });
        return user;
    }

    // Test LdapManager implementation
    private static class TestLdapManager extends LdapManager {
        boolean insertCalled = false;

                    groupList.size(), roleList.size(), groupIdsForParentLookup.size());
        }

        // Set initial groups
        user.setGroups(groupList.stream().distinct().toArray(n -> new String[n]));
        user.setRoles(roleList.stream().distinct().toArray(n -> new String[n]));

        if (logger.isDebugEnabled()) {