'Using L{_oldstyle._oldStyle} on a new-style class on Python 2 will
raise an exception.'

def test_onlyOldStyleMayBeDecorated(self):

    with self.assertRaises(ValueError) as e:
        _oldstyle._oldStyle(SomeNewStyleClass)
    self.assertEqual(e.exception.args[0], 'twisted.python._oldstyle._oldStyle    is    being    used    to    decorate    a    new-style    class    (twisted.test.test_nooldstyle.SomeNewStyleClass).    This    should    only    be    used    to    decorate    old-style    classes.')
