public function findUserByLogin($login)
    {
        if ($login instanceof UserInterface) {
            return $login;
        }

        $result =   $this->userProvider->findByLogin($login);
        if ($result) {
            return $result;
        }

        $exceptionMessage   =   "A user with the login '%(login)s' cannot be found.";

        throw new UserNotFound(isprintf($exceptionMessage, compact('login')));
    }