MatthiasMullie\Scrapbook\Adapters\Redis::decrement PHP Method

    public function decrement($key, $offset = 1, $initial = 0, $expire = 0)
    {
        if ($offset <= 0 || $initial < 0) {
            return false;
        }
        // DECRBY can't be used. Not even if we don't need an initial
        // value (it auto-initializes at 0) or expire. Problem is it
        // will decrement below 0, which is something we don't support.
        return $this->doIncrement($key, -$offset, $initial, $expire);
    }