Golang API response 400

I can't see were is my error every time i try to run it i get nothing when i print some of the key variables i got this :

print longURL

> http://www.example.com

print &output

> &{400 Bad Request 400 HTTP/1.1 1 1 map[X-Frame-Options:[SAMEORIGIN]
> X-Xss-Protection:[1; mode=block] Server:[GSE]
> Alternate-Protocol:[443:quic] Content-Type:[application/json;
> charset=UTF-8] Date:[Thu, 12 Jun 2014 02:10:33 GMT] Expires:[Thu, 12
> Jun 2014 02:10:33 GMT] Cache-Control:[private, max-age=0]
> X-Content-Type-Options:[nosniff]] 0xc2100fe940 -1 [chunked] false
> map[] 0xc2100581a0}

// c0de urlShort


package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"
)

type apiResponse struct {
	Id, Kind, LongURL string
}

func main() {

	longURL := os.Args[len(os.Args)-1]

	body := bytes.NewBufferString(fmt.Sprintf(
		`{"longURL":"%s"}`,
		longURL))

	request, err := http.NewRequest(
		"POST",
		"https://www.googleapis.com/urlshortener/v1/url",
		body)

	request.Header.Add("Content-Type", "application/json")

	client := http.Client{}

	response, err := client.Do(request)

	if err != nil {
		log.Fatal(err)
	}

	outputAsBytes, err := ioutil.ReadAll(response.Body)
	response.Body.Close()

	var output apiResponse
	err = json.Unmarshal(outputAsBytes, &output)

	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%s", output.Id)

}

Instead of normal response, you are getting this:

{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "required",
    "message": "Required",
    "locationType": "parameter",
    "location": "resource.longUrl"
   }
  ],
  "code": 400,
  "message": "Required"
 }
}

It says that you are missing required parameter: longUrl. Notice that it's long Url not long URL

This code works for me:

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
)

type apiResponse struct {
    Id, Kind, LongURL string
}

func main() {

    longURL := os.Args[len(os.Args)-1]

    body := bytes.NewReader([]byte(fmt.Sprintf(
        `{"longUrl":"%s"}`,
        longURL)))


    request, err := http.NewRequest(
        "POST",
        "https://www.googleapis.com/urlshortener/v1/url",
        body)

    request.Header.Add("Content-Type", "application/json")

    client := http.Client{}

    response, err := client.Do(request)

    if err != nil {
        log.Fatal(err)
    }

    outputAsBytes, err := ioutil.ReadAll(response.Body)
    response.Body.Close()

    fmt.Println(string(outputAsBytes))

    var output apiResponse
    err = json.Unmarshal(outputAsBytes, &output)

    if err != nil {
        log.Fatal(err)
    }

    fmt.Printf("%s", output)

}