How to use the tblib.mongo.mongo function in tblib

def create_file():
    """保存表单上传文件到 GridFS
    """

    if 'file' not in request.files or request.files['file'].filename == '':
        raise NotFound()

    id = mongo.save_file(request.files['file'].filename, request.files["file"])

    _, ext = path.splitext(request.files['file'].filename)

    return json_response(id='{}{}'.format(id, ext))

def file_response(id, download=False):
    # 获取 GridFS 文件
    try:
        file = GridFS(mongo.db).get(id)
    except NoFile:
        raise NotFound()

    # 将 GridFS 文件对象包装为一个 WSGI 文件对象
    data = wrap_file(request.environ, file, buffer_size=1024 * 255)
    # 创建一个 Flask Response 对象来响应文件内容
    response = current_app.response_class(
        data,
        mimetype=file.content_type,
        direct_passthrough=True,
    )
    # 设置内容长度响应头
    response.content_length = file.length
    # 设置内容最后修改时间 和 Etag 响应头，浏览器可根据这些信息来判断文件内容是否有更新
    response.last_modified = file.upload_date
    response.set_etag(file.md5)