public function distributeExpire(EventInterface $event)/*# : bool */
    {
        $dist = $this->distribution;
        $item = $event->getParam('item');

        if ($item instanceof CacheItemExtendedInterface) {
            // expire ttl
            $ttl = $item->getExpiration()->getTimestamp() - time();

            // percentage
            $percent = (rand(0, $dist * 2) - $dist) * 0.001;

            // new expire ttl
            $new_ttl = (int) round($ttl + $ttl * $percent);
            $item->expiresAfter($new_ttl);
        }

        return true;
    }