Go SFTP下载文件| 3PP服务器返回`不可提取`

Question

if f, err = s.client.Open(path.Join(remotePath, fileName)); err != nil {
return err
}

if err = os.MkdirAll(localPath, os.ModePerm); err != nil {
    return err
}
if localFile, err = os.Create(path.Join(localPath, fileName)); err != nil {
    return err
}
if n, err := f.WriteTo(localFile); err != nil {
return err
}