Inheritance: System.EventArgs
    private void ManageDownloadProgress(DownloadOperation downloadOperation)
    {
      string downloadWhoseProgressChanged = downloadOperation.Guid.ToString();
      var downloadProgressStatus = downloadOperation.Progress.Status;

      int receivedPercentage = 100;
      double bytesReceived = downloadOperation.Progress.BytesReceived;
      double bytesLeftToReceive = downloadOperation.Progress.TotalBytesToReceive;
      if (bytesLeftToReceive > 0)
      {
        receivedPercentage = (int)((bytesReceived * 100) / bytesLeftToReceive);
      }
      ProgressEventArgs args = new ProgressEventArgs(receivedPercentage, downloadWhoseProgressChanged);
      DownloadProgressChanged(this, args);
    }