show it as the response (JSON Schema).
                * Serialization: you could return an arbitrary object and the
                    `response_model` would be used to serialize that object into the
                    corresponding JSON.
                * Filtering: the JSON sent to the client will only contain the data

                                    if subtype == "json" or subtype.endswith("+json"):
                                        json_body = await request.json()
                            if json_body != Undefined:
                                body = json_body
                            else:
                                body = body_bytes
            except json.JSONDecodeError as e: