public void CountLetters()
{
LinkTypes.LetterCounter letterCount = LinkTypes.CountLetters("system");
Assert.AreEqual(2, letterCount.CountFor('s'));
Assert.AreEqual(1, letterCount.CountFor('y'));
Assert.AreEqual(1, letterCount.CountFor('t'));
Assert.AreEqual(1, letterCount.CountFor('e'));
Assert.AreEqual(1, letterCount.CountFor('m'));
Assert.AreEqual(0, letterCount.CountFor('a'));
Assert.AreEqual(0, letterCount.CountFor('b'));
}
