@Transactional(readOnly = false)
 public void deleteGroup(Long groupId, Long userId) {
   Group group = userRepository.loadGroupById(groupId);
   if (group.checkOwnership(userId)) {
     logger.info("Deleting " + group);
     userRepository.deleteGroup(group);
   }
 }
 public Group getGroupById(Long groupId) {
   return userRepository.loadGroupById(groupId);
 }