langchain/document_loaders/chatgpt.py/concatenate_rows
def concatenate_rows(message: dict, title: str) -> str:
    if not message:
        return ""

    sender = message["author"]["role"] if message["author"] else "unknown"
    text = message["content"]["parts"][0]
    date = datetime.datetime.fromtimestamp(message["create_time"]).strftime(
        "%Y-%m-%d %H:%M:%S"
    )
    return f"{title} - {sender} on {date}: {text}\n\n"