code: private void parseUsersAuthentication(final XMLExtendedStreamReader reader,
                                            final ModelNode realmAddress, final List<ModelNode> list)
              throws XMLStreamException {
          final ModelNode usersAddress = realmAddress.clone().add(AUTHENTICATION, USERS);
          list.add(Util.getEmptyOperation(ADD, usersAddress));
  
          while (reader.hasNext() && reader.nextTag() != END_ELEMENT) {
              requireNamespace(reader, namespace);
              final Element element = Element.forName(reader.getLocalName());
              switch (element) {
                  case USER: {
                      parseUser(reader, usersAddress, list);
                      break;
                  }
                  default: {
                      throw unexpectedElement(reader);
                  }
              }
          }
      }
docs: The users element defines users within the domain model, it is a simple authentication for some out of the box users.