private Execution createExecution(Chain<Searcher> chain) {
        IndexModel indexModel = new IndexModel(createSearchDefinitionOne());
        return new Execution(chain, Execution.Context.createContextStub(new IndexFacts(indexModel)));
    }
Creates a search chain which always returns a result with one hit containing information given in this

@param sdName the search definition type of the returned hit
@param content the content of the "dynteaser" field of the returned hit
container-search/src/test/java/com/yahoo/search/rendering/JsonRendererTestCase.java