如何正确将XML解组到Go结构

I have xml which I want to unmarshal into Session struct

type Session struct {
    XMLName xml.Name `xml:"response"`
    status  string `xml:"status,attr`
    Result  Result `xml:"result"`
}
type Result struct {
    tmo_udp string `xml:"tmo-udp"`
    tmo_tcp string `xml:"tmo-tcp"`
    }
var session Session
    xml.Unmarshal(htmlData, &session)
    fmt.Println(string(htmlData))
    fmt.Println("-------------------------------------------------")
    fmt.Println(session)

but got nothing when trying to print it

<response status="success"><result>
  <tmo-udp>30</tmo-udp>
  <tmo-tcp>3600</tmo-tcp>
</result></response>
-------------------------------------------------
{{ response}  {                                }}