private Hit createHit(String id, double relevancy, String... fieldNames) {
        Hit h = new Hit(id, relevancy);
        h.setFillable();
        int i = 0;
        for (String field : fieldNames) {
            h.setField(field, ++i);
        }
        return h;
    }
Test translation of fields and sources in YQL to the associated concepts in Vespa.
container-search/src/test/java/com/yahoo/search/yql/YqlFieldAndSourceTestCase.java