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.");
}