public function onFormSuccess(FormEvent $event)
    {
        $form = $event->getForm();

        $result = $this->createResult($form);

        if ($form->getStoreResults()) {
            $this->storeResult($form, $result);
        }

        if ($form->getSendMail()) {
            $this->sendMail($form, $result);
        }

        $successUrl = $form->getSuccessUrl();

        if ($successUrl != null) {
            $redirectResponse = new RedirectResponse($successUrl);
            $redirectResponse->send();
        }
    }