Class key

IPython/utils/tests/test_path.py:173–179

        env.pop(key, None)

    class key:
        def __enter__(self):
            pass
        def Close(self):
            pass
        def __exit__(*args, **kwargs):
            pass

    with patch.object(wreg, 'OpenKey', return_value=key()), \
         patch.object(wreg, 'QueryValueEx', return_value=[abspath(HOME_TEST_DIR)]):