def test_adding_x_to_x(self):
""" Test adding 10 + 10 """
numeral_a = Roman('x')
numeral_b = Roman('x')
self.assertEqual('xx', numeral_a.add(numeral_b))
self.assertEqual('xx', numeral_b.add(numeral_a))
def test_adding_l_to_i(self):
""" Test adding 50 + 1 """
numeral_a = Roman('l')
numeral_b = Roman('i')
self.assertEqual('li', numeral_a.add(numeral_b))
self.assertEqual('li', numeral_b.add(numeral_a))
def test_adding_xi_to_vi(self):
""" Test adding 11 + 6 """
numeral_a = Roman('xi')
numeral_b = Roman('vi')
self.assertEqual('xvii', numeral_a.add(numeral_b))
self.assertEqual('xvii', numeral_b.add(numeral_a))
