protected function isValidTwoFactorBackup(AuthenticatableTwoFactorContract $user, int $token): bool
    {
        $backup = array_get($user->getTwoFactor(), 'totp.backup', []);
        $result = mb_strlen($token) === 10 && in_array($token, $backup);
        ! $result || $this->invalidateTwoFactorBackup($user, $token);

        return $result;
    }