assertFalse(queryFieldConfig.isSortField("anyfield"));
        assertFalse(queryFieldConfig.isSortField(""));
        assertFalse(queryFieldConfig.isSortField(null));
    }

    public void test_isFacetField_withEmptyArray() {
        queryFieldConfig.setFacetFields(new String[] {});

        assertFalse(queryFieldConfig.isFacetField("anyfield"));
        assertFalse(queryFieldConfig.isFacetField(""));