def test_equals_2(self):
     self.assertEqual(add("1101", "101"), "10010")
 def test_equals_2(self):
     self.assertEqual(add('1101', '101'), '10010')
 def test_equals_5(self):
     self.assertEqual(add("00", "0"), "0")
 def test_equals_5(self):
     self.assertEqual(add('00', '0'), '0')