You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: httpTrace.go
    path of file: ./repos/Mastering_Go_ZH_CN/eBook/examples/chapter12
    
    the code of the file until where you have to start completion: package main

import (
	"fmt"
	"io"
	"net/http"
	"net/http/httptrace"
	"os"
)

func main() {
	if len(os.Args) != 2 {
		fmt.Println("Usage: URL\n")
		return
	}
	URL := os.Args[1]
	client := http.Client{}

	req, _ := http.NewRequest("GET", URL, nil)
	trace := &httptrace.ClientTrace{
		GotFirstResponseByte: func() {
			fmt.Println("First response byte!")
		},
		GotConn: func(connInfo httptrace.GotConnInfo) {
			fmt.Printf("Got Conn: %+v\n", connInfo)
		},
		DNSDone: func(dnsInfo httptrace.DNSDoneInfo) {
			fmt.Printf("DNS Info: %+v\n", dnsInfo)
		},

    
func main() {
	if len(os.Args) != 2 {
		fmt.Println("Usage: URL\n")
		return
	}
	URL := os.Args[1]
	client := http.Client{}

	req, _ := http.NewRequest("GET", URL, nil)
	trace := &httptrace.ClientTrace{
		GotFirstResponseByte: func() {
			fmt.Println("First response byte!")
		},
		GotConn: func(connInfo httptrace.GotConnInfo) {
			fmt.Printf("Got Conn: %+v\n", connInfo)
		},
		DNSDone: func(dnsInfo httptrace.DNSDoneInfo) {
			fmt.Printf("DNS Info: %+v\n", dnsInfo)
		},
		ConnectStart: func(network, addr string) {
			fmt.Println("Dial start")
		},
		ConnectDone: func(network, addr string, err error) {
			fmt.Println("Dial done")
		},
		WroteHeaders: func() {
			fmt.Println("Wrote headers")
		},
	}

	req = req.WithContext(httptrace.WithClientTrace(req.Context(), trace))
	fmt.Println("Requesting data from server!")
	_, err := http.DefaultTransport.RoundTrip(req)
	if err != nil {
		fmt.Println(err)
		return
	}

	response, err := client.Do(req)
	if err != nil {
		fmt.Println(err)
		return
	}
	io.Copy(os.Stdout, response.Body)
}