def test_convertOtherSerialBitsMismatch(self):
        """
        L{SerialNumber._convertOther} raises L{TypeError} if the other
        SerialNumber instance has a different C{serialBits} value.
        """
        s1 = SerialNumber(0, serialBits=8)
        s2 = SerialNumber(0, serialBits=16)

        self.assertRaises(
            TypeError,
            s1._convertOther,
            s2
        )

        L{SerialNumber._convertOther} raises L{TypeError} if the other
        SerialNumber instance has a different C{serialBits} value.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_rfc1982.py