public Result get(Chain<Searcher> chain, Query query) {
            Map<Query, Result> resultsToFillForAChain = resultsToFill.computeIfAbsent(chain, k -> new IdentityHashMap<>());

            Result resultsToFillForAChainAndQuery = resultsToFillForAChain.get(query);
            if (resultsToFillForAChainAndQuery == null) {
                resultsToFillForAChainAndQuery = new Result(query);
                resultsToFillForAChain.put(query, resultsToFillForAChainAndQuery);
            }

            return resultsToFillForAChainAndQuery;
        }
Returns a result to fill for a query and chain, by creating it if necessary
container-search/src/main/java/com/yahoo/search/federation/FederationSearcher.java