def test_cross_off_adds_guessed_letter_to_list_of_guessed_letters(self):
# arrange
alphabet = Alphabet()
letter = "a"
# act
alphabet.cross_off(letter)
# assert
assert letter in alphabet.guessed_letters
def test_already_guessed_returns_true_if_letter_guessed(self):
# arrange
alphabet = Alphabet()
letter = "h"
alphabet.cross_off(letter)
# act
result = alphabet.already_guessed("h")
# assert
assert result is True