| 854 | self.assertEqual(c.exception.args, (42,)) |
| 855 | |
| 856 | class F(dict): |
| 857 | def __init__(self): |
| 858 | # An instance variable __missing__ should have no effect |
| 859 | self.__missing__ = lambda key: None |
| 860 | f = F() |
| 861 | with self.assertRaises(KeyError) as c: |
| 862 | f[42] |