Setting up http trailers in Golang

1. Trailers are of header type in go.
2. You can only read trailer after reading body

package main
import (
	"io/ioutil"
	"log"
	"net/http"
	"net/http/httptest"
)
func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("/sendTrailer", func(w http.ResponseWriter, req *http.Request) {
		w.Header().Add("Trailer", "AtEnd1")
		w.WriteHeader(http.StatusOK)
		w.Header().Set("AtEnd1", "value 1")
	})
	ts := httptest.NewServer(mux)
	defer ts.Close()
	req, _ := http.NewRequest("GET", ts.URL+"/sendTrailer", nil)
	res, _ := http.DefaultClient.Do(req)
	ioutil.ReadAll(res.Body) // reading for sake of receiving trailer
	defer res.Body.Close()
	log.Printf("%+v", res.Trailer)
}

example: https://goplay.space/#DcjchhxYBSy

PS: gist