public function client($name, Closure $closure = null)
    {
        if ($this->has($name)) {
            /** @var Service $service */
            $service = $this->services[$name];

            if (is_null($service->getClient())) {
                $client = new Client($service->getWsdl(), $service->getOptions(), $service->getHeaders());
              
                $service->client($client);
            } else {
                $client = $service->getClient();
            }

            return $closure($client);
        }

        throw new ServiceNotFound("Service '" . $name . "' not found.");
    }