# By being a new field, no inheritance will be passed as is. A new model
            # will always be created.
            # TODO: remove when deprecating Pydantic v1
            self.secure_cloned_response_field: Optional[
                ModelField
            ] = create_cloned_field(self.response_field)
        else:
            self.response_field = None  # type: ignore

                    license name used for the API.
                * `identifier`: (`str`) An [SPDX](https://spdx.dev/) license expression
                    for the API. The `identifier` field is mutually exclusive of the `url`
                    field. Available since OpenAPI 3.1.0, FastAPI 0.99.0.
                * `url`: (`str`) A URL to the license used for the API. This MUST be
                    the format of a URL.