private function getSplit($key, $parts)
    {
        $keys = array();
        for ($i = 0; $i < $parts; $i++) {
            $keys[] = $key.$i;
        }

        $values = $this->memcached->getMulti($keys);

        if (false === $values) {
            $msg = sprintf(
                'Unable to retrieve split key "%s": %s.',
                $key,
                $this->memcached->getResultMessage()
            );

            $this->getLogger()->log(LogLevel::NOTICE, $msg);
            throw new \RuntimeException($msg);
        }

        $value = implode('', $values);

        return $value;
    }