code: func (b *Bot) Raw(method string, payload interface{}) ([]byte, error) {
  	url := fmt.Sprintf("%s/bot%s/%s", b.URL, b.Token, method)
  
  	var buf bytes.Buffer
  	if err := json.NewEncoder(&buf).Encode(payload); err != nil {
  		return []byte{}, wrapSystem(err)
  	}
  
  	resp, err := b.client.Post(url, "application/json", &buf)
  	if err != nil {
  		return []byte{}, errors.Wrap(err, "http.Post failed")
  	}
  	resp.Close = true
  	defer resp.Body.Close()
  	json, err := ioutil.ReadAll(resp.Body)
  	if err != nil {
  		return []byte{}, wrapSystem(err)
  	}
  
  	return json, nil
  }
docs: // Raw lets you call any method of Bot API manually.