public function indexAction($username = null, $unauthorized = false)
    {
        if ($this->securityContext->getInterceptedRequest() || $unauthorized) {
            $this->response->setStatus(401);
        }
        if ($this->authenticationManager->isAuthenticated()) {
            $this->redirect('index', 'Backend\Backend');
        }
        $currentDomain = $this->domainRepository->findOneByActiveRequest();
        $currentSite = $currentDomain !== null ? $currentDomain->getSite() : $this->siteRepository->findDefault();
        $this->view->assignMultiple([
            'styles' => array_filter($this->settings['userInterface']['backendLoginForm']['stylesheets']),
            'username' => $username,
            'site' => $currentSite
        ]);
    }