* `url`: A URL to the target host. This URL supports Server Variables
                and MAY be relative, to indicate that the host location is relative
                to the location where the OpenAPI document is being served. Variable
                substitutions will be made when a variable is named in `{`brackets`}`.

        self.endpoint = endpoint
        if isinstance(response_model, DefaultPlaceholder):
            return_annotation = get_typed_return_annotation(endpoint)
            if lenient_issubclass(return_annotation, Response):
                response_model = None
            else:
                response_model = return_annotation
        self.response_model = response_model
        self.summary = summary