private void assertSelects(String providerName, SearchChainRegistry registry) {
        QueryProfile profile = new QueryProfile("test");
        profile.set("source.news.provider", providerName, null);
        Query query = new Query(QueryTestCase.httpEncode("?query=test&model.sources=news"), profile.compile(null));
        Result result = new Execution(registry.getComponent("default"), Execution.Context.createContextStub(registry)).search(query);
        assertEquals(1, result.hits().size());
        assertNotNull(result.hits().get(providerName + ":1"));
    }
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