Drupal 8使用事件订阅者在每个页面加载时设置cookie

I am trying to set a cookie on every page load. I did some research and found that event subscribers are the way to go. I created a custom module with event. It starts the event on every page load but the problem is with the cookies.

The $event object has property called response but it is always null. Therefore i cannot set any cookies.

 class LanguageCookieSubscriber implements EventSubscriberInterface 
 {

    protected $event;

    protected $cookieValue;

    public function init(GetResponseEvent $event) {

      $this->event = $event;

      $cookie = new Cookie("client_language_cookie", $this->cookieValue, 0, '/', NULL, FALSE);

      $this->event->getResponse()->headers->setCookie($cookie);
   }
 }

I also tried to set the response object. Then I can set the cookie but the page will come blank.

  $response = new Response();
  $this->event->setResponse($response);
  $cookie = new Cookie("client_language_cookie", $this->cookieValue, 0, '/', NULL, FALSE);
  $this->event->getResponse()->headers->setCookie($cookie);

Any ideas how can i solve this? I need to display the page user has requested and only set cookie.

Thanks in advance.