         mutating func addRequest(request: Request) {
 
             requests.append(request)
-            print("requests.count: \(requests.count)")
         }
 
         func requestsWithURL(URL: NSURL) -> [Request] {

        }
    }

    struct RequestPool {

        private var requests: [Request]


                                } else {
                                    if let data = NSData(contentsOfURL: URL), image = UIImage(data: data) {
                                        sharedInstance.completeRequestsWithURL(URL, image: image)

                                    } else {
                                        dispatch_async(dispatch_get_main_queue()) {
                                            sharedInstance.requestPool.removeRequestsWithURL(URL)
                                        }
                                    }
                                }
