@Override
    public String toString() {
        return "AclConfig{" +
            "globalWhiteAddrs=" + globalWhiteAddrs +
            ", plainAccessConfigs=" + plainAccessConfigs +
            '}';
    }
@Test
    public void testToStringWithNullValues() {
        AclConfig aclConfig = new AclConfig();
        String result = aclConfig.toString();
        assertNotNull("toString should not be null", result);
        assertEquals("toString should match", "AclConfig{globalWhiteAddrs=null, plainAccessConfigs=null}", result);
    }