code: func (a *API) FetchWorksheet(cid CIDType) (*Worksheet, error) {
  	if cid == nil || *cid == "" {
  		return nil, fmt.Errorf("Invalid worksheet CID [none]")
  	}
  
  	worksheetCID := string(*cid)
  
  	matched, err := regexp.MatchString(config.WorksheetCIDRegex, worksheetCID)
  	if err != nil {
  		return nil, err
  	}
  	if !matched {
  		return nil, fmt.Errorf("Invalid worksheet CID [%s]", worksheetCID)
  	}
  
  	result, err := a.Get(string(*cid))
  	if err != nil {
  		return nil, err
  	}
  
  	if a.Debug {
  		a.Log.Printf("[DEBUG] fetch worksheet, received JSON: %s", string(result))
  	}
  
  	worksheet := new(Worksheet)
  	if err := json.Unmarshal(result, worksheet); err != nil {
  		return nil, err
  	}
  
  	return worksheet, nil
  }
docs: // FetchWorksheet retrieves worksheet with passed cid.