@BeforeEach
    public void setUp() throws Exception {
        Query query = new Query("?query=test");

        Result result = new Result(query);
        Hit hit = createHit("lastHit", .1d, FIELD1, FIELD2, FIELD3);
        result.hits().add(hit);

        DocumentSourceSearcher mockBackend = new DocumentSourceSearcher();
        mockBackend.addResult(query, result);

        mockBackend.addSummaryClassByCopy(DEFAULT_SUMMARY_CLASS, List.of(FIELD1, FIELD2, FIELD3));
        mockBackend.addSummaryClassByCopy(SORTABLE_ATTRIBUTES_SUMMARY_CLASS, List.of(FIELD2));
        mockBackend.addSummaryClassByCopy(THIRD_OPTION, List.of(FIELD3));

        searchChain = new Chain<>(new FieldFiller(schemaInfo()), mockBackend);
        context = Execution.Context.createContextStub();
        execution = new Execution(searchChain, context);
    }
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