code: func newURLEncodedRequest(method, endpoint string, params map[string]string) (*http.Request, error) {
  	urlValues := url.Values{}
  	for k, v := range params {
  		urlValues.Add(k, v)
  	}
  
  	req, err := http.NewRequest(method, endpoint, strings.NewReader(urlValues.Encode()))
  	if err != nil {
  		return nil, err
  	}
  	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
  
  	return req, nil
  }
docs: // urlEncodedRequest returns a new url encoded request.