def test_check_three_digits_four(self): self.assertEqual(check_three_digits(4), 'IV')
def test_check_three_digits_nine_hundred(self): self.assertEqual(check_three_digits(900), 'CM')
def test_check_three_digits_nine_hundred_ninety_nine(self): self.assertEqual(check_three_digits(999), 'CMXCIX')
def test_check_three_digits_five_hundred(self): self.assertEqual(check_three_digits(500), 'D')
def test_check_three_digits_one(self): self.assertEqual(check_three_digits(1), 'I')
def test_check_three_digits_one_hundred(self): self.assertEqual(check_three_digits(100), 'C')
def test_check_three_digits_four_hundred(self): self.assertEqual(check_three_digits(400), 'CD')
def test_check_three_digits_ninety(self): self.assertEqual(check_three_digits(90), 'XC')
def test_check_three_digits_ninety_nine(self): self.assertEqual(check_three_digits(99), 'XCIX')
def test_check_three_digits_fifty(self): self.assertEqual(check_three_digits(50), 'L')
def test_check_three_digits_sixty(self): self.assertEqual(check_three_digits(60), 'LX')
def test_check_three_digits_forty(self): self.assertEqual(check_three_digits(40), 'XL')
def test_check_three_digits_twenty(self): self.assertEqual(check_three_digits(20), 'XX')
def test_check_three_digits_ten(self): self.assertEqual(check_three_digits(10), 'X')
def test_check_three_digits_six(self): self.assertEqual(check_three_digits(6), 'VI')
def test_check_three_digits_five(self): self.assertEqual(check_three_digits(5), 'V')