def test_valid_long_luhn_number(): assert Card._luhn_valid("5523104176235661500") == True
def test_invalid_luhn_number(): assert Card._luhn_valid("4111111111111112") == False
def test_valid_short_luhn_number(): assert Card._luhn_valid("349") == True
def test_valid_luhn_number(): assert Card._luhn_valid("1635136358093212") == True