'Check same msg for exceptions with 0 args and overridden __str__'

def test_0_args_with_overridden___str__(self):

    for msg in ('foo', u'foo'):
        self.check_same_msg(ExcWithOverriddenStr(msg=msg), msg)
    e = ExcWithOverriddenStr(msg=u'f\xf6\xf6')
    self.assertRaises(UnicodeEncodeError, str, e)
    self.assertEqual(unicode(e), u'f\xf6\xf6')
