func GbkToUtf8(s []byte) ([]byte, error) {    reader := transform.NewReader(bytes.NewReader(s), simplifiedchinese.GBK.NewDecoder())    d, e := ioutil.ReadAll(reader)    if e != nil {        return nil, e    }    return d, nil}func Utf8ToGbk(s []byte) ([]byte, error) {    reader := transform.NewReader(bytes.NewReader(s), simplifiedchinese.GBK.NewEncoder())    d, e := ioutil.ReadAll(reader)    if e != nil {        return nil, e    }    return d, nil}