MatthiasMullie\Scrapbook\Psr6\Item::expiresAfter PHP Method

    public function expiresAfter($time)
    {
        if ($time instanceof DateInterval) {
            $expire = new DateTime();
            $expire->add($time);
            // convert datetime to unix timestamp
            $this->expire = (int) $expire->format('U');
        } elseif (is_int($time)) {
            $this->expire = time() + $time;
        } elseif (is_null($time)) {
            // this is allowed, but just defaults to infinite
            $this->expire = 0;
        } else {
            throw new InvalidArgumentException('Invalid time: ' . serialize($time) . '. Must be integer or ' . 'instance of DateInterval.');
        }
        $this->changed = true;
        return $this;
    }