public async void Undo()
{
if (undos.Count > 0)
{
try
{
var change = await CreateChange("Redo");
redos.Push(change);
var undo = undos.Pop();
var block = await Task.Run(() => _itemSerializer.DeserializeContents(undo.Model));
_sheetController.ResetPage();
_sheetController.DeserializePage(block);
}
catch (Exception ex)
{
Debug.Print(ex.Message);
Debug.Print(ex.StackTrace);
}
}
}