private static void addSourceForProvider(SearchChainResolver.Builder builder, FederationConfig.Target target,
                                             FederationConfig.Target.SearchChain searchChain, boolean isDefaultProvider)
    {
        builder.addSourceForProvider(
                ComponentId.fromString(target.id()),
                ComponentId.fromString(searchChain.providerId()),
                ComponentId.fromString(searchChain.searchChainId()),
                isDefaultProvider, federationOptions(searchChain),
                searchChain.documentTypes());
    }
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