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 testGetTwice() {
        ConfigGetter<AppConfig> getter = new ConfigGetter<>(AppConfig.class);
        AppConfig config = getter.getConfig("raw:message \"one\"");
        assertEquals("one", config.message());
        config = getter.getConfig("raw:message \"two\"");
        assertEquals("two", config.message());
    }