private function getServiceClass($name)
    {
        $serviceId = $this->getServiceId($name);
        $parameterId = $serviceId.'.class';
        if ($this->container->hasParameter($parameterId)) {
            $class = $this->container->getParameter($parameterId);
        } elseif (array_key_exists($name, $this->options)) {
            $class = $this->options[$name];
        } else {
            throw new \RuntimeException(sprintf('Undefined "%s" service class.', $name));
        }
        return $class;
    }