private ConfigRetriever createConfigRetriever() {
        String configId = dirConfigSource.configId();
        CloudSubscriberFactory subscriberFactory = new CloudSubscriberFactory(dirConfigSource.configSource());
        Set<ConfigKey<? extends ConfigInstance>> keys = new HashSet<>();
        keys.add(new ConfigKey<>(Bootstrap1Config.class, configId));
        keys.add(new ConfigKey<>(Bootstrap2Config.class, configId));
        return new ConfigRetriever(keys, subscriberFactory);
    }
@author gjoranv
@author Tony Vaagenes
@author ollivir
container-core/src/test/java/com/yahoo/container/di/ConfigRetrieverTest.java