public function createProxyClassInstance($service)
    {
        $file = $this->getProxyFilename(get_class($service));
        
        if (file_exists($file)) {
            require_once $file;
        } else {
            throw new Exception\RuntimeException(
                sprintf('Proxy class for service "%s" has not been initialized', get_class($service)));
        }
        
        $proxyService = $this->getProxyClassName(get_class($service));
        return new $proxyService($service);
    }