public function getCacheTtl()
    {
        if ($this->hasOption(static::OPTION_CACHE_PERSISTENCE_TTL)) {
            $cacheTtl = $this->getOption(static::OPTION_CACHE_PERSISTENCE_TTL);
            if (!is_null($cacheTtl)) {
                return $cacheTtl;
            }
        }

        return static::CACHE_PERSISTENCE_DEFAULT_TTL;
    }