internal virtual void CheckDuplicate(TaskDialogItem itemToExclude)
 {
     CheckDuplicateId(itemToExclude, _id);
 }
 internal override void CheckDuplicate(TaskDialogItem itemToExclude)
 {
     CheckDuplicateButton(_type, itemToExclude);
     base.CheckDuplicate(itemToExclude);
 }