String[] fields = {};
        queryFieldConfig.setApiResponseFields(fields);

        assertNotNull(queryFieldConfig.apiResponseFieldSet);
        assertEquals(0, queryFieldConfig.apiResponseFieldSet.size());
    }

    public void test_isApiResponseField() {
        String[] fields = { "field1", "field2", "field3" };
        queryFieldConfig.setApiResponseFields(fields);

        // Test valid API response fields

                    fessConfig.getIndexFieldClickCount(), //
                    fessConfig.getIndexFieldFavoriteCount());
        }
        if (apiResponseFieldSet == null) {
            setApiResponseFields(fessConfig.getQueryAdditionalApiResponseFields(//
                    SCORE_SORT_VALUE, //
                    fessConfig.getResponseFieldContentDescription(), //