def test_4(self): self.assertEqual(roman_to_int('IV'), 4)
def test_1(self): self.assertEqual(roman_to_int('I'), 1)
def test_222(self): self.assertEqual(roman_to_int('CCXXII'), 222)
def test_1904(self): self.assertEqual(roman_to_int('MCMIV'), 1904)
def test_21(self): self.assertEqual(roman_to_int('XXI'), 21)