}

    @Test
    public void test_convert_nullUrl() {
        assertNull(duplicateHostHelper.convert(null));
    }

    @Test
    public void test_convert_withNullList() {
        DuplicateHostHelper helper = new DuplicateHostHelper();
        helper.duplicateHostList = null;

        String url = "http://test.com";
        String result = helper.convert(url);