code: func (s LoginSession) NewCaptchaIden() (string, error) {
  	req := &request{
  		url: "https://www.reddit.com/api/new_captcha",
  		values: &url.Values{
  			"api_type": {"json"},
  		},
  		cookie:    s.cookie,
  		useragent: s.useragent,
  	}
  	body, err := req.getResponse()
  	if err != nil {
  		return "", err
  	}
  
  	// Get the CAPTCHA iden from the JSON.
  	type Response struct {
  		JSON struct {
  			Errors [][]string
  			Data   struct {
  				Iden string
  			}
  		}
  	}
  
  	r := new(Response)
  	err = json.NewDecoder(body).Decode(r)
  	if err != nil {
  		return "", err
  	}
  
  	return r.JSON.Data.Iden, nil
  }
docs: // NewCaptchaIden gets a new captcha iden from reddit