def test_RomanNumerals(self):
assert (RomanNumerals.to_roman(1000) == 'M')
assert (RomanNumerals.to_roman(1990) == 'MCMXC')
assert (RomanNumerals.from_roman('XXI') == 21)
assert (RomanNumerals.from_roman('MMVIII') == 2008)
