if comment is not None:
        for line in comment.splitlines():
            lines.append(f": {line}")

    if event is not None:
        lines.append(f"event: {event}")

    if data_str is not None:
        for line in data_str.splitlines():
            lines.append(f"data: {line}")

    if id is not None:
        lines.append(f"id: {id}")

    if retry is not None:
        lines.append(f"retry: {retry}")

                            data_str: str | None = item.raw_data
                        elif item.data is not None:
                            if hasattr(item.data, "model_dump_json"):
                                data_str = item.data.model_dump_json()
                            else:
                                data_str = json.dumps(jsonable_encoder(item.data))
                        else: