code: func (e CloseErrors) Error() string {
  	var errMsgs []string
  
  	for _, err := range []error(e) {
  		if err == nil {
  			continue
  		}
  		errMsgs = append(errMsgs, err.Error())
  	}
  
  	return strings.Join(errMsgs, ", ")
  }
docs: // Error implements error interface.