public void IterationTestCount()
        {
            var letter = new AlphabetLetter('a');
            int i      = 1;

            while (!letter.Eoa())
            {
                letter = letter.GetNextLetter();
                i++;
            }

            Assert.True(i == 26);
        }
        public void IterationLetterCheck()
        {
            var letter = new AlphabetLetter('a');
            int i      = 1;

            while (!letter.Eoa())
            {
                Assert.True(letter.NumericValue == i);

                if (i == 16)
                {
                    Assert.True(letter == 'p');
                }

                letter = letter.GetNextLetter();
                i++;
            }

            Assert.True(i == 26);
        }