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;

            }
        }, "activityHelper");

        String[] groupNames = ldapUser.getGroupNames();
        assertNotNull(groupNames);
        assertEquals(2, groupNames.length);
        assertEquals("group1", groupNames[0]);
        assertEquals("group2", groupNames[1]);
    }

    @Test
    public void test_getGroupNames_empty() {
        // Test when no groups match the prefix