private void AdjustCircle(object sender, SizeChangedEventArgs e)
        {
            TicTacToeField control    = sender as TicTacToeField;
            double         width      = e.NewSize.Width;
            double         height     = e.NewSize.Height;
            double         squareSize = Math.Min(width, height);

            control.Width  = squareSize;
            control.Height = squareSize;
            control.Shapes.TryGetValue(TicTacToe.Sign.O, out Shape Circle);
            Circle.Width           = squareSize - 6 < 0 ? squareSize : squareSize - 6;
            Circle.Height          = Circle.Width;
            Circle.StrokeThickness = 0.15 * squareSize;
        }
        private static void OnColumnChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            TicTacToeField control = d as TicTacToeField;

            control.OnColumnChanged(e);
        }