protected function handle304Response(RequestInterface $request, Response $validateResponse, Response $response)
    {
        static $replaceHeaders = array('Date', 'Expires', 'Cache-Control', 'ETag', 'Last-Modified');

        // Make sure that this response has the same ETag
        if ($validateResponse->getEtag() != $response->getEtag()) {
            return false;
        }

        // Replace cached headers with any of these headers from the
        // origin server that might be more up to date
        $modified = false;
        foreach ($replaceHeaders as $name) {
            if ($validateResponse->hasHeader($name)) {
                $modified = true;
                $response->setHeader($name, $validateResponse->getHeader($name));
            }
        }

        // Store the updated response in cache
        if ($modified && $this->canCache->canCacheResponse($response)) {
            $this->storage->cache($request, $response);
        }

        return true;
    }