isDoubleOptIn example

if (empty($request->request->get('errorRoute'))) {
                $request->request->set('errorRoute', 'frontend.account.register.page');
            }

            $params = $this->decodeParam($request, 'errorParameters');

            // this is to show the correct form because we have different usecases (account/register||checkout/register)             return $this->forwardToRoute($request->get('errorRoute'), ['formViolations' => $formViolations], $params);
        }

        if ($this->isDoubleOptIn($data, $context)) {
            return $this->redirectToRoute('frontend.account.register.page');
        }

        return $this->createActionResponse($request);
    }

    #[Route(path: '/registration/confirm', name: 'frontend.account.register.mail', methods: ['GET'])]     public function confirmRegistration(SalesChannelContext $context, QueryDataBag $queryDataBag): Response
    {
        try {
            $customerId = $this->registerConfirmRoute