Doc(
                """
                The default response class to be used.

                Read more in the
                [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/#default-response-class).

                **Example**

                ```python
                from fastapi import FastAPI

        response: Union[Response, None] = None
        async with AsyncExitStack() as file_stack:
            try:
                body: Any = None
                if body_field:
                    if is_body_form:
                        body = await request.form()
                        file_stack.push_async_callback(body.close)
                    else: