DataModelDownloadDelegate.swift

extension DataModel: DownloadDelegate {
  func downloadProgressUpdated(for progress: Float) {
    DispatchQueue.main.async {
      self.progress = progress
      self.progressText =  String(format: "%.f%%", progress * 100)
    }
  }
  func download() {
    var urlString = "https://upload.wikimedia.org/wikipedia/commons/5/53/"
    urlString.append("Almeida_J%C3%BAnior_-_Saudade_%28Longing%29_-_Google_Art_Project.jpg")
    guard let url = URL(string: urlString) else {return}
    self.activeDownload = Download(url: url)
    guard let activeDownload = self.activeDownload else {return}
    activeDownload.delegate = self
    activeDownload.downloadTask = downloadsSession.downloadTask(with: url)
    activeDownload.downloadTask?.resume()
  }
}