Google App Engine Go HTTP发布[] byte

package appimport (    "http"    "appengine"    "appengine/urlfetch"    "bytes"    "fmt")func init() {    http.HandleFunc("/post", post)}func post(w http.ResponseWriter, r *http.Request) {    c := appengine.NewContext(r)    bs := []byte{1,2,3}    buf := bytes.NewBuffer(bs)    client := http.Client{Transport: &urlfetch.Transport{Context:c}}    if _, err := client.Post("http://localhost:8080/", "application/octet-stream", buf); err != nil {        fmt.Println(err)    }}