public synchronized T getConfig(String configId) {
        try (ConfigSubscriber subscriber = new ConfigSubscriber()) {
            ConfigHandle<T> handle = subscriber.subscribe(clazz, configId);
            subscriber.nextConfig(true);
            return handle.getConfig();
        }
    }
Returns an instance of the config class specified in the constructor.

@param configId a config id to use when getting the config
@return an instance of a config class
config/src/main/java/com/yahoo/config/subscription/ConfigGetter.java