private void Kanban_DragOver(object sender, KanbanDragOverEventArgs e)
 {
     if (e.SourceColumn == menu)
     {
         e.Cancel = true;
     }
 }
 void Handle_DragOver(object sender, KanbanDragOverEventArgs e)
 {
     if (e.TargetColumn.Title.ToString() == "Menu")
     {
         e.Cancel = true;
     }
 }