Contao\CoreBundle\Exception\ResponseException::__construct PHP Method

    public function __construct(Response $response, \Exception $previous = null)
    {
        if (!$response->headers->has('X-Status-Code')) {
            $response->headers->set('X-Status-Code', $response->getStatusCode());
        }
        $this->response = $response;
        parent::__construct('This exception has no message. Use $exception->getResponse() instead.', 0, $previous);
    }

 /**
  * Constructor.
  *
  * @param \Exception|null $previous
  */
 public function __construct(\Exception $previous = null)
 {
     parent::__construct(new Response('', 204), $previous);
 }