golang http.get : connection not closed

gistfile1.go

// makes a request to a service with the get parameters passed in parameter
// returns a Response struct containing the response
func getVastPlayer(v url.Values) (Response, float64, error) {
	resp := Response{}

	u := VAST_URL + v.Encode()

	t1 := time.Now()
	myresp, err := http.Get(u)
	defer myresp.Body.Close()

	t2 := time.Now()

	if err != nil {
		return resp, -1, errors.New("request error (" + err.Error() + ")")
	}

	if vastResp.StatusCode != 200 {
		return resp, -1, errors.New("request error (status code : " + strconv.Itoa(myresp.StatusCode) + ")")
	}

	if err := json.NewDecoder(myresp.Body).Decode(&resp); err != nil {
		return resp, -1, errors.New("response decoding error (" + err.Error() + ")")
	}


	responseTime := float64(t2.Sub(t1).Nanoseconds() / 1000000)

	return resp, responseTime, nil
}