public void SingleValidLine_ReturnsTrue(int index, string word) { WordHexagon hexagon = new WordHexagon(4); Assert.IsTrue(hexagon.ValidateDiagonalLines()); hexagon.SetDiagonalLineAtIndex(index, word); Assert.IsTrue(hexagon.ValidateDiagonalLines(), $"After setting {word} at index {index}, it should be valid."); }