private void assertUseByDefault(FederationConfig config, String sourceName, String providerName,
                                    boolean expectedValue) {

        FederationConfig.Target target = getTarget(config.target(), sourceName);
        FederationConfig.Target.SearchChain searchChain = getProvider(target, providerName);
        assertEquals(expectedValue, searchChain.useByDefault());
    }
Test generated config for federation.
@author Tony Vaagenes
config-model/src/test/java/com/yahoo/vespa/model/container/search/searchchain/FederationTest.java