private Result getSearchChainGroup(Hit hit, Result result, UniqueExecutionsToResults uniqueExecutionsToResults) {
        @SuppressWarnings("unchecked")
        Chain<Searcher> chain = (Chain<Searcher>) hit.getSearcherSpecificMetaData(this);
        Query query = hit.getQuery() !=null ? hit.getQuery() : result.getQuery();

        return uniqueExecutionsToResults.get(chain, query);
    }
The name of the query property containing the source name added to the query to each source by this
container-search/src/main/java/com/yahoo/search/federation/FederationSearcher.java