public void TestAverageString()
{
Assert.AreEqual("four", Extension.AverageString("zero nine five two"));
Assert.AreEqual("three", Extension.AverageString("four six two three"));
Assert.AreEqual("three", Extension.AverageString("one two three four five"));
Assert.AreEqual("four", Extension.AverageString("five four"));
Assert.AreEqual("zero", Extension.AverageString("zero zero zero zero zero"));
Assert.AreEqual("two", Extension.AverageString("one one eight one"));
Assert.AreEqual("n/a", Extension.AverageString(""));
Assert.AreEqual("n/a", Extension.AverageString("pjebqo, six, four, one, four"));
}
