Set<String> resolveSchemas(Query query) {
        Set<String> restrict = query.getModel().getRestrict();
        if (restrict == null || restrict.isEmpty()) {
            Set<String> sources = query.getModel().getSources();
            return (sources == null || sources.isEmpty())
                    ? schema2Searcher.keySet()
                    : resolveSourceSubset(sources);
        } else {
            return filterValidDocumentTypes(restrict);
        }
    }
Do not use, for internal testing purposes only. *
container-search/src/main/java/com/yahoo/prelude/cluster/ClusterSearcher.java