code: func (bot *BotAPI) GetFile(config FileConfig) (File, error) {
  	v := url.Values{}
  	v.Add("file_id", config.FileID)
  
  	resp, err := bot.MakeRequest("getFile", v)
  	if err != nil {
  		return File{}, err
  	}
  
  	var file File
  	json.Unmarshal(resp.Result, &file)
  
  	bot.debugLog("GetFile", v, file)
  
  	return file, nil
  }
docs: // GetFile returns a File which can download a file from Telegram.
  //
  // Requires FileID.