private List<ResolveResult> resolveClustersWithDocument(ComponentSpecification sourceRef, Properties sourceToProviderMap) {

        if (hasOnlyName(sourceRef)) {
            List<ResolveResult> clusterSearchChains = new ArrayList<>();

            List<String> clusters = schema2Clusters.getOrDefault(sourceRef.getName(), List.of());
            for (String cluster : clusters) {
                clusterSearchChains.add(resolveClusterSearchChain(cluster, sourceRef, sourceToProviderMap));
            }

            if ( ! clusterSearchChains.isEmpty())
                return clusterSearchChains;
        }
        return List.of(new ResolveResult(createForMissingSourceRef(sourceRef)));
    }
Maps a source reference to search chain invocation specs.

@author Tony Vaagenes
container-search/src/main/java/com/yahoo/search/federation/sourceref/SourceRefResolver.java