private void ActivityItemsRemove(ActivityTreeItem.enGroupType groupType)
 {
     foreach (var item in ActivityItems)
     {
         if (item.GroupType == groupType)
         {
             ActivityItems.Remove(item);
             break;
         }
     }
 }
        private void OnActivityDeleted(ActivityDeletedEventArgs args)
        {
            CurrentDialog = null;
            RaisePropertyChanged(nameof(CurrentDialog));

            var deletedActivity = ActivityItems.FirstOrDefault(activityItem => activityItem.Activity.Id == args.DeletedActivityId);

            if (deletedActivity is null)
            {
                return;
            }

            ActivityItems.Remove(deletedActivity);
        }