code: public function serve()
      {
          $message = $this->getMessage();
  
          // Handle Messages.
          if (isset($message['MsgType'])) {
              return parent::serve();
          }
  
          Log::debug('OpenPlatform Request received:', [
              'Method' => $this->request->getMethod(),
              'URI' => $this->request->getRequestUri(),
              'Query' => $this->request->getQueryString(),
              'Protocal' => $this->request->server->get('SERVER_PROTOCOL'),
              'Content' => $this->request->getContent(),
          ]);
  
          // If sees the `auth_code` query parameter in the url, that is,
          // authorization is successful and it calls back, meanwhile, an
          // `authorized` event, which also includes the auth code, is sent
          // from WeChat, and that event will be handled.
          if ($this->request->get('auth_code')) {
              return new Response(self::SUCCESS_EMPTY_RESPONSE);
          }
  
          $this->handleEventMessage($message);
  
          return new Response(self::SUCCESS_EMPTY_RESPONSE);
      }
docs: {@inheritdoc}