def test_repr(self):
        """
        L{SerialNumber.__repr__} returns a string containing number and
        serialBits.
        """
        self.assertEqual(
            '<SerialNumber number=123 serialBits=32>',
            repr(SerialNumber(123, serialBits=32))
        )

        L{SerialNumber.__repr__} returns a string containing number and
        serialBits.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_rfc1982.py