def test_requiredArgumentWithNoneValueRaisesTypeError(self):
        """
        L{ListOf.toBox} raises C{TypeError} when passed a value of L{None}
        for the argument.
        """
        stringList = amp.ListOf(amp.Integer())
        self.assertRaises(
            TypeError, stringList.toBox, b'omitted', amp.AmpBox(),
            {'omitted': None}, None)

        L{ListOf.toBox} raises C{TypeError} when passed a value of L{None}
        for the argument.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_amp.py