public void ExH4_TestMultipleSubstitution()
{
Debug.WriteLine("Bad dog, d, f => Baf fog");
Assert.AreEqual("Baf fog", ExH4.Substitute("Bad dog", 'd', 'f'));
}
public void ExH4_TestNoSubstitution()
{
Debug.WriteLine("Bad dog, e, o => Bad dog");
Assert.AreEqual("Bad dog", ExH4.Substitute("Bad dog", 'e', 'o'));
}