code: @Override
      public void validate(ValidationHelper helper, Context context, String key, Contact t) {
          if (t != null) {
              String url = t.getUrl();
              if (url != null) {
                  if (!ValidatorUtils.isValidURI(url)) {
                      final String message = Tr.formatMessage(tc, "contactInvalidURL", url);
                      helper.addValidationEvent(new ValidationEvent(ValidationEvent.Severity.ERROR, context.getLocation("url"), message));
                  }
              }
  
              String email = t.getEmail();
              if (email != null) {
                  if (!ValidatorUtils.isValidEmailAddress(email)) {
                      final String message = Tr.formatMessage(tc, "contactInvalidEmail", email);
                      helper.addValidationEvent(new ValidationEvent(ValidationEvent.Severity.ERROR, context.getLocation("email"), message));
                  }
              }
          }
      }
docs: {@inheritDoc}