private List<ResolveResult> resolveSources(Set<String> sourcesInQuery, Properties properties) {
        List<ResolveResult> result = new ArrayList<>();
        Set<String> sources = virtualSourceResolver.resolve(sourcesInQuery);

        for (String source : sources) {
            result.addAll(sourceRefResolver.resolve(asSourceSpec(source), properties));
        }

        return List.copyOf(result);
    }
TODO This is probably a dirty hack for bug 4711376. There are probably better ways.
But I will leave that to trd-processing@

@param group the merging hitgroup to be updated if necessary
@param orderer the per provider hit orderer
@return he hitorderer chosen
container-search/src/main/java/com/yahoo/search/federation/FederationSearcher.java