private function setEtag(Request $request, Response $cachedResponse)
    {
        if ($etag = $cachedResponse->getHeader('ETag')) {
            $request->addHeader('If-None-Match', $etag);
        }
    }
private function setEtag(Request $request, Response $cachedResponse)
    {
        if ($etag = $cachedResponse->getHeader('ETag')) {
            $request->addHeader('If-None-Match', $etag);
        }
    }
private function setEtag ( Request $ request , Response $ cachedResponse ) { if ( $ etag = $ cachedResponse -> getHeader ( 'ETag' ) ) { $ request -> addHeader ( 'If-None-Match' , $ etag ) ; } }
Sets ETag if available in the cached response

@param Request  $request
@param Response $cachedResponse
Sets ETag if available in the cached response