class KillSwitch

class KillSwitch implements ResponsePolicyInterface {
  
  /**
   * A flag indicating whether the kill switch was triggered.
   *
   * @var bool
   */
  protected $kill = FALSE;
  
  /**
   * {@inheritdoc}
   */
  public function check(Response $response, Request $request) {
    if ($this->kill) {
      return static::DENY;
    }
  }
  
  /**
   * Deny any page caching on the current request.
   */
  public function trigger() {
    $this->kill = TRUE;
  }

}