public void test_GetClue_blank_when_no_guesses()
        {
            var game = new HangmanGame()
            {
                CurrentGameWord = "Test",
                GuessedLetters = new HashSet<char>()
            };

            const string expected = "_ _ _ _ ";
            Assert.AreEqual(expected, game.GetClue(game.CurrentGameWord));
        }
        public void test_GetClue_includes_guessess()
        {
            var game = new HangmanGame()
            {
                CurrentGameWord = "Test",
                GuessedLetters = new HashSet<char>()
            };

            game.GuessedLetters.Add('e');
            const string expected = "_ e _ _ ";
            Assert.AreEqual(expected, game.GetClue(game.CurrentGameWord));
        }