    def test_nested_context_for_oneOf(self):
        """
        We traverse into nested contexts (a oneOf containing an error in a
        nested oneOf here).
        """

        schema = {
            "properties": {
                "foo": {
                    "oneOf": [
                        {"type": "string"},
                        {
                            "oneOf": [
                                {"type": "string"},
                                {
                                    "properties": {
                                        "bar": {"type": "array"},
                                    },
                                },
                            ],
                        },
                    ],
                },
            },
        }
        best = self.best_match_of(instance={"foo": {"bar": 12}}, schema=schema)
        self.assertEqual(best.validator_value, "array")
We traverse into nested contexts (a oneOf containing an error in a
nested oneOf here).
jsonschema/tests/test_exceptions.py