code: func (client *Client) newGETRequest(url string) (*http.Request, error) {
  	request, err := http.NewRequest(
  		http.MethodGet,
  		url,
  		nil,
  	)
  	if err != nil {
  		return nil, err
  	}
  
  	request.Header = http.Header{}
  	request.Header.Set("Accept", "application/json")
  	request.Header.Set("Content-Type", "application/json")
  	request.Header.Set("User-Agent", client.userAgent)
  
  	return request, nil
  }
docs: // newGETRequest returns a constructed HTTP.Request with some defaults.
  // Defaults are applied when Request options are not filled in.