def test_equals_2(self):
     self.assertEqual(solution(4), "IV")
 def test_equals(self):
     self.assertEqual(solution(1), "I")
 def test_equals_3(self):
     self.assertEqual(solution(6), "VI")
 def test_equals_2(self):
     self.assertEqual(solution(4), 'IV')
 def test_equals(self):
     self.assertEqual(solution(1), 'I')
 def test_equals_3(self):
     self.assertEqual(solution(6), 'VI')