public function make($host)
    {
        $host = $this->resolver->resolve($host, '/');
        $hash = md5($host);

        if (isset($this->instances[$hash])) {
            return $this->instances[$hash];
        }

        $validator = new Validator(
            $this->validator,
            new ResourceNormalizer
        );
        $instance = new Server(
            $this->capabilities->make($host),
            new Client(
                $this->loader->make($host),
                $this->serializer,
                $this->resolver,
                $validator,
                $this->dispatcher,
                $this->http
            )
        );
        $this->instances[$hash] = $instance;

        return $instance;
    }