default Item parse(String queryToParse, String filterToParse, Language parsingLanguage,
                       Set<String> toSearch, IndexFacts indexFacts, String defaultIndexName) {
        if (indexFacts == null)
            indexFacts = new IndexFacts();
        return parse(queryToParse, filterToParse, parsingLanguage, indexFacts.newSession(toSearch, Set.of()), defaultIndexName);
    }
Returns the raw result from parsing, <i>not</i> wrapped in a QueryTree
instance. This may also be null, as opposed to using
{@link Parser#parse(com.yahoo.search.query.parser.Parsable)}.
container-search/src/main/java/com/yahoo/prelude/query/parser/CustomParser.java