restorePersistenceManager() is present in singleton class . So the session gets created in init method and delegate get set here override  init() { super.init()         bitrate = SettingsManager.shared.downloadQuailty ?? 9728000.0         // streamManager = StreamManager()         // Create the configuration for the AVAssetDownloadURLSession.         let backgroundConfiguration = URLSessionConfiguration.background(withIdentifier: "unique-Identifier")         // Create the AVAssetDownloadURLSession using the configuration.         assetDownloadURLSession =             AVAssetDownloadURLSession(configuration: backgroundConfiguration,                                       assetDownloadDelegate: self, delegateQueue: OperationQueue.main)     }