private FederationSearcher createMultiProviderFederationSearcher() {
        FederationOptions options = new FederationOptions();
        SearchChainResolver.Builder builder = new SearchChainResolver.Builder();

        ComponentId provider1 = new ComponentId("provider1");
        ComponentId provider2 = new ComponentId("provider2");
        ComponentId news = new ComponentId("news");
        builder.addSearchChain(provider1, options, List.of());
        builder.addSearchChain(provider2, options, List.of());
        builder.addSourceForProvider(news, provider1, provider1, true, options, List.of());
        builder.addSourceForProvider(news, provider2, provider2, false, options, List.of());

        return new FederationSearcher(builder.build(), Map.of());
    }
Test for federation searcher. The searcher is also tested in
com.yahoo.prelude.searcher.test.BlendingSearcherTestCase.

@author Arne Bergene Fossaa
container-search/src/test/java/com/yahoo/search/federation/FederationSearcherTestCase.java