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

    public void test_getGroupNames_empty() {
        // Test when no groups match the prefix
        ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            @Override
            public String getRoleSearchGroupPrefix() {