Symfony\Component\HttpFoundation\Response::setCache PHP Method

    public function setCache(array $options)
    {
        if ($diff = array_diff(array_keys($options), array('etag', 'last_modified', 'max_age', 's_maxage', 'private', 'public'))) {
            throw new \InvalidArgumentException(sprintf('Response does not support the following options: "%s".', implode('", "', array_values($diff))));
        }

        if (isset($options['etag'])) {
            $this->setEtag($options['etag']);
        }

        if (isset($options['last_modified'])) {
            $this->setLastModified($options['last_modified']);
        }

        if (isset($options['max_age'])) {
            $this->setMaxAge($options['max_age']);
        }

        if (isset($options['s_maxage'])) {
            $this->setSharedMaxAge($options['s_maxage']);
        }

        if (isset($options['public'])) {
            if ($options['public']) {
                $this->setPublic();
            } else {
                $this->setPrivate();
            }
        }

        if (isset($options['private'])) {
            if ($options['private']) {
                $this->setPrivate();
            } else {
                $this->setPublic();
            }
        }

        return $this;
    }

 /**
  * @param Request $request
  * @param $storageKey
  *
  * @return Response
  */
 protected function createFileResponse(Request $request, $storageKey)
 {
     $response = new Response();
     $parts = explode('/', $storageKey);
     $file = $this->getFile($parts[0]);
     if (!$file) {
         return $response->setContent('File not found.')->setStatusCode(Response::HTTP_NOT_FOUND);
     }
     if ($request->get('dl') !== null) {
         $filename = $file->getFilename();
         if (count($parts) > 1) {
             $filename = $parts[count($parts) - 1];
         }
         $filenameFallback = filter_var($filename, FILTER_SANITIZE_URL);
         if ($filenameFallback != $filename) {
             $guesser = ExtensionGuesser::getInstance();
             $extension = filter_var($guesser->guess($file->getMimeType()) ?: $file->getExtension(), FILTER_SANITIZE_URL);
             $filenameFallback = $file->getStorageKey() . ($extension ? '.' . $extension : '');
         }
         $response->headers->set('Content-Disposition', $response->headers->makeDisposition(ResponseHeaderBag::DISPOSITION_ATTACHMENT, $filename, $filenameFallback));
     } else {
         $response->setCache(array('etag' => $file->getStorageKey(), 'last_modified' => $file->getCreatedAt()));
         if ($response->isNotModified($request)) {
             return $response;
         }
     }
     $response->setContent($file->getContents());
     $response->headers->set('Content-type', $file->getMimeType());
     $response->headers->set('Content-length', $file->getSize());
     return $response;
 }