Я следовал инструкциямВот для кэширования HLS, но элемент управления никогда не достигает ни одного из делегатов (AVAssetDownloadDelegate).

Я что-то пропустил? Вот код я написал

- (void)setupAssetDownloader {
    NSURL *assetURL = [NSURL URLWithString:@"STREAMING_HOST/video/hls/3729170.m3u8"];
    AVURLAsset *hlsAsset = [AVURLAsset assetWithURL:assetURL];

    urlSessionConfiguration = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:@"assetDowloadConfigIdentifier"];
    avAssetDownloadSession = [AVAssetDownloadURLSession sessionWithConfiguration:urlSessionConfiguration assetDownloadDelegate:self delegateQueue:[NSOperationQueue mainQueue]];

    // Download movie
    avAssetDownloadTask = [avAssetDownloadSession assetDownloadTaskWithURLAsset:hlsAsset assetTitle:@"downloadedMedia" assetArtworkData:nil options:nil];

//@{AVAssetDownloadTaskMinimumRequiredMediaBitrateKey : @(300000)}


    [avAssetDownloadTask resume];

    AVPlayerItem *playerItem = [[AVPlayerItem alloc] initWithAsset:avAssetDownloadTask.URLAsset];
    AVPlayer *player = [[AVPlayer alloc ] initWithPlayerItem:playerItem];
    AVPlayerLayer *playerLayer = [[AVPlayerLayer alloc ] init];
    [playerLayer setPlayer:player];
    [playerLayer setFrame:self.view.frame];
    [self.view.layer addSublayer:playerLayer];
    [player play];
}

#pragma mark - AVAssetDownloadDelegate

- (void)URLSession:(NSURLSession *)session assetDownloadTask:(AVAssetDownloadTask *)assetDownloadTask didResolveMediaSelection:(AVMediaSelection *)resolvedMediaSelection {

}
- (void)URLSession:(NSURLSession *)session assetDownloadTask:(AVAssetDownloadTask *)assetDownloadTask didLoadTimeRange:(CMTimeRange)timeRange totalTimeRangesLoaded:(NSArray<NSValue *> *)loadedTimeRanges timeRangeExpectedToLoad:(CMTimeRange)timeRangeExpectedToLoad {
    NSInteger percent = 0;
    for (NSValue *value in loadedTimeRanges) {
        CMTimeRange timeRange = [value CMTimeRangeValue];
        percent += CMTimeGetSeconds(timeRange.duration) / CMTimeGetSeconds(timeRangeExpectedToLoad.duration);
    }
    percent *= 100;
    NSLog(@"Progress: %ld", (long)percent);
}

- (void)URLSession:(NSURLSession *)session assetDownloadTask:(AVAssetDownloadTask *)assetDownloadTask didFinishDownloadingToURL:(NSURL *)location {
    NSString *localPath = location.relativePath;
    NSLog(@"localPath: %@", localPath);
    // TODO: Play downloaded file
    // IMPORTANT: Don't move this file to another location.
}