@Override
 public ValidationResult validate(final Map<String, String> properties) {
   final DefaultValidationResult result = new DefaultValidationResult();
   for (final Validator validator : validators) {
     final ValidationResult validationResult = validator.validate(properties);
     if (!validationResult.isValid()) {
       result.add(validationResult.violations());
     }
   }
   if (result.isValid()) {
     return ValidationResult.VALID;
   }
   return result;
 }