public static Context createContextStub(SearchChainRegistry searchChainRegistry,
                                                IndexFacts indexFacts,
                                                Linguistics linguistics) {
            return createContextStub(searchChainRegistry, indexFacts, SchemaInfo.empty(), linguistics);
        }
Creates a Context instance where everything except the given arguments is empty. This is for unit testing.
container-search/src/main/java/com/yahoo/search/searchchain/Execution.java