/**
  * Checks for valid CSRF token provided along the request if controller
  * execution requires a valid CSRF token.
  *
  * Returns TRUE in case no CSRF token is required by the controller or a valid token
  * has been provided along the request.
  * Otherwise returns FALSE.
  *
  * @return bool
  */
 protected function checkCsrfToken()
 {
     return $this->isCsrfTokenRequired() ? Application::getSecurityHandler()->getCsrfProtector()->checkCsrfToken($this->getRequest()) : true;
 }