private void search(Query query, Execution execution, Target target, Result mergedResults) {
        mergeResult(query, target, mergedResults, search(query, execution, target).orElse(createSearchChainTimedOutResult(query, target)));
    }
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