Contao\CoreBundle\EventListener\PrettyErrorScreenListener::isBackendUser PHP Method

    private function isBackendUser()
    {
        $token = $this->tokenStorage->getToken();
        if (null === $token) {
            return false;
        }
        $user = $token->getUser();
        if (null === $user) {
            return false;
        }
        return $user instanceof BackendUser;
    }