public void ValueShouldNotBeNullWhenLetterIsInstantiated()
        {
            var letter = new Letter();

            Assert.IsNotNull(letter.Value);
        }
        public void LetterShouldNotBeNullWhenInstantiated()
        {
            var letter = new Letter();

            Assert.NotNull(letter);
        }
        public void ValueShouldHaveDefaultValueA()
        {
            var letter = new Letter();

            Assert.AreEqual(letter.Value, 'a');
        }
        public void IsFoundShouldBeFalseWhenLetterIsInstantiated()
        {
            var letter = new Letter();

            Assert.IsFalse(letter.IsFound);
        }