public synchronized T getConfig(String configId) {
        try (ConfigSubscriber subscriber = new ConfigSubscriber()) {
            ConfigHandle<T> handle = subscriber.subscribe(clazz, configId);
            subscriber.nextConfig(true);
            return handle.getConfig();
        }
    }
@Test
    public void testGetFromFile() {
        ConfigGetter<AppConfig> getter = new ConfigGetter<>(AppConfig.class);
        AppConfig config = getter.getConfig("file:src/test/resources/configs/foo/app.cfg");
        verifyFooValues(config);
    }