MatthiasMullie\Scrapbook\Adapters\MemoryStore::doIncrement PHP Метод

    protected function doIncrement($key, $offset, $initial, $expire)
    {
        if (!$this->exists($key)) {
            $this->set($key, $initial, $expire);
            return $initial;
        }
        $value = $this->get($key);
        if (!is_numeric($value) || $value < 0) {
            return false;
        }
        $value += $offset;
        // value can never be lower than 0
        $value = max(0, $value);
        $this->set($key, $value, $expire);
        return $value;
    }