addSubscriber($IOSubscriber); $googleDNSResolver = new GoogleDNS(); $googleDNSResolver->addSubscriber($IOSubscriber); $cloudFlareResolver = new CloudFlare(); $cloudFlareResolver->addSubscriber($IOSubscriber); $digResolver = new \WP_Ultimo\Dependencies\RemotelyLiving\PHPDNS\Resolvers\Dig(new SpatieDNS(), new Dig()); $digResolver->addSubscriber($IOSubscriber); $chainResolver = new Chain($cloudFlareResolver, $googleDNSResolver, $localSystemResolver); $cachedResolver = new Cached(new FilesystemAdapter(), $chainResolver); $cachedResolver->addSubscriber($IOSubscriber);