code: public List<ValidationMessage<Origin>> getMessages(String messageKey) {
  
          List<ValidationMessage<Origin>> result = new ArrayList<ValidationMessage<Origin>>();
  
          for (ValidationResult validationResult : results) {
              for (ValidationMessage<Origin> message : validationResult.getMessages()) {
                  if (messageKey.equals(message.getMessageKey())) {
                      result.add(message);
                  }
              }
          }
          return result;
      }
docs: Finds validation messages by the message key.
  
  @param messageKey a message key of the message
  @return a collection of found validation messages