protected virtual void OnCellLeave(CellPointedEventArgs e)
        {
            this.CellLeave?.Invoke(this, e);
            FakeCheckBox fcb = GetCheckBox(e.Coordinate.Value.Column, e.Coordinate.Value.Row);

            if (fcb != null)
            {
                this.RedrawCell(e.Coordinate, fcb.Checked);
            }
        }
 protected virtual void OnCellEnter(CellPointedEventArgs e)
 {
     this.CellEnter?.Invoke(this, e);
     this.RedrawCell(e.Coordinate);
 }