protected function checkCacheVersion()
    {
        $fileName = $this->getVersionFileName();

        if (!file_exists($fileName)) {
            return false;
        }

        $version = md5($this->boltVersion);
        $cached = file_get_contents($fileName);

        if ($version === $cached) {
            return true;
        }
        $this->versionChange = true;

        return false;
    }