public void When_Player_X_puts_three_in_a_row_it_should_win()
        {
            // Arrange 
            var row1 = new[] { "X", "X", "O" }; 
            var row2 = new[] { "X", "O", "O" };
            var row3 = new[] { " ", " ", " " };
            var game = new Game(row1, row2, row3);

            // Act

            game.PlayAt(2, 0);

            // Assert

            Assert.AreEqual("X", game.Winner);
        }
        public void When_9_rows_are_filled_and_there_is_no_winner_It_should_be_Cats()
        {
            // Arrange 
            var row1 = new[] { "X", "X", "O" };
            var row2 = new[] { "O", "O", "X" };
            var row3 = new[] { " ", "O", "X" };
            
            var game = new Game(row1, row2, row3);

            // Act

            game.PlayAt(2, 0);

            // Assert

            Assert.AreEqual(null, game.Winner);
        }