public void FindAndReplaceTest_ForUserInputa_b()
        {
            FindAndReplace testLetter = new FindAndReplace();

            Assert.Equal("b", testLetter.FindAndReplaceResult("a", "a", "b"));
        }
        public void FindAndReplaceTest_ForUserInputSelectWord_word()
        {
            FindAndReplace testWord = new FindAndReplace();

            Assert.Equal("Hello universe", testWord.FindAndReplaceResult("Hello world", "world", "universe"));
        }
        public void FindAndReplaceTest_ForUserInputSelectedPartWord_sentence()
        {
            FindAndReplace testSentence = new FindAndReplace();

            Assert.Equal("My cat loves hotcats", testSentence.FindAndReplaceResult("My dog loves hotdogs", "dog", "cat"));
        }
        public void FindAndReplaceTest_ForUserInputCaplitalization_capitalization()
        {
            FindAndReplace testCapitalization = new FindAndReplace();

            Assert.Equal("My CAT loves hotCATs", testCapitalization.FindAndReplaceResult("My doG loVes hotDogs", "dog", "cat"));
        }