def test_I(self):
self.assertEqual(sum("I", "I"), "II")
self.assertEqual(sum("I", "II"), "III")
self.assertEqual(sum("II", "II"), "IIII")
def test_VIIII(self):
self.assertEqual(sum("V", "IIII"), "VIIII")
self.assertEqual(sum("VI", "III"), "VIIII")
self.assertEqual(sum("VIII", "I"), "VIIII")
def test_L(self):
self.assertEqual(sum("XX", "XXX"), "L")
self.assertEqual(sum("XXVI", "XXIIII"), "L")
def test_X(self):
self.assertEqual(sum("V", "V"), "X")
self.assertEqual(sum("VI", "IIII"), "X")
self.assertEqual(sum("VII", "III"), "X")
self.assertEqual(sum("II", "VIII"), "X")