public void ValidateOtherDiagonalWin()
        {
            var gameBoard = new TestableGameBoard
            {
                Marks = new Mark?[] { null, null, Mark.X, null, Mark.X, null, Mark.X, null, null }
            };

            Assert.True(WinHelper.IsWinningMove(gameBoard));
        }
        public void ValidateNoWin()
        {
            var gameBoard = new TestableGameBoard();

            Assert.False(WinHelper.IsWinningMove(gameBoard));
        }