protected function getProxyClassDirAndCreate($namespace)
    {
        $path = str_replace("\\", DIRECTORY_SEPARATOR, $namespace);
        $dir = $this->config->getProxyRootDir() . DIRECTORY_SEPARATOR . $path;
        if (!Util::createDirIfNotExists($dir)) {
            throw new InitiallyRpcException("Proxy builder error: get proxy class dir and create it");
        }

        return $dir;
    }