protected void addUserFromCallbackOperation(String userId) {
   try {
     boolean userExists = pm.find(UserImpl.class, userId) != null;
     if (!StringUtils.isEmpty(userId) && !userExists) {
       UserImpl user = new UserImpl(userId);
       pm.persist(user);
     }
   } catch (Throwable t) {
     // logger.log(Level.SEVERE, "Unable to add user " + userId);
   }
 }
 protected void addGroupFromCallbackOperation(String groupId) {
   try {
     boolean groupExists = pm.find(GroupImpl.class, groupId) != null;
     if (!StringUtils.isEmpty(groupId) && !groupExists) {
       GroupImpl group = new GroupImpl(groupId);
       pm.persist(group);
     }
   } catch (Throwable t) {
     // logger.log(Level.WARNING, "UserGroupCallback has not been registered.");
   }
 }