Lumen开发：lumen源码解读之初始化(6)——启动(run)

    /**
     * Run the application and send the response.
     *
     * @param  SymfonyRequest|null  $request
     * @return void
     */
    public function run($request = null)
    {
        echo "------------run  start   \n";
        $response = $this->dispatch($request);

        if ($response instanceof SymfonyResponse) {
            $response->send();
        } else {
            echo (string) $response;
        }

        if (count($this->middleware) > 0) {
            $this->callTerminableMiddleware($response);
        }
        echo "------------run  end   \n";
    }