code: func (service *IYOEmailAddressValidationService) IsConfirmed(request *http.Request, key string) (confirmed bool, err error) {
  	info, err := service.getEmailAddressValidationInformation(request, key)
  	if err != nil {
  		return
  	}
  	if info == nil {
  		err = ErrInvalidOrExpiredKey
  		return
  	}
  	confirmed = info.Confirmed
  	return
  }
docs: //IsConfirmed checks wether a validation request is already confirmed