pkg/httputil/httputil.go
func GracefulClose(resp *http.Response) {
	io.Copy(ioutil.Discard, resp.Body)
	resp.Body.Close()
}
func GracefulClose(resp *http.Response) {
	io.Copy(ioutil.Discard, resp.Body)
	resp.Body.Close()
}
// GracefulClose drains http.Response.Body until it hits EOF
// and closes it. This prevents TCP/TLS connections from closing,
// therefore available for reuse.
// Borrowed from golang/net/context/ctxhttp/cancelreq.go.