public static Task Report <TNotification>(this ProgressObserver <ProgressWithPercentage <TNotification> > observer, TNotification notification, double progressPercentage)
 {
     return(observer.Report(new ProgressWithPercentage <TNotification>(notification, progressPercentage)));
 }
 public static Task ReportComplete <TNotification>(this ProgressObserver <ProgressWithPercentage <TNotification> > observer, TNotification notification)
 {
     return(observer.ReportComplete(new ProgressWithPercentage <TNotification>(notification, double.MaxValue, true)));
 }