/**
  * Handle request in stack
  * 
  * @param   object  $request  Request
  * @return  mixed
  */
 public function handle(Request $request)
 {
     $response = $this->next($request);
     $filename = $this->app['moderator']->getPath();
     // Ensure the file exist
     if (!file_exists($filename)) {
         // Return message
         header('HTTP/1.1 404 Not found');
         exit;
     }
     // Initiate a new content server
     $server = new Server();
     $server->disposition('inline');
     $server->acceptranges(true);
     $server->allowXsendFile();
     $server->filename($filename);
     // Serve up the file
     $result = $server->serve();
     return $response;
 }