public static function privateNoExpireCache(
        ResponseInterface $response,
        /*# int */ $cacheTime = 120
    )/*# : ResponseInterface */ {
        $maxAge = $cacheTime * 60;
        return $response
            ->withAddedHeader('Cache-Control', "private, max-age={$maxAge}, pre-check={$maxAge}")
            ->withAddedHeader('Last-Modified', self::timeStamp());
    }