     }
     
     private func download(_ item: Item, _ cached: IsCached, _ callback: @escaping (Result) -> ()) {
-        guard !canceled else {
+        guard !isCancelled else {
             callback(.cancel)
             return
         }

        
        contentLength(of: first) { result in
            switch result {
            case .canceled, .failure:
                callback(result)
            case let .success(headLength, headCached):
                let tail = items[(items.startIndex + 1)..<items.endIndex]

        if needsPreciseProgress {
            contentLength(of: items[0..<items.count]) { result in
                switch result {
                case .cancel:
                    self.complete(with: .cancel)
                case let .failure(error):
                    self.complete(with: .failure(error))
