public void addUserToGroup(UserGroup userGroup, User user)
{
DbValidationUtils.assertPersisted(userGroup);
DbValidationUtils.assertPersisted(user);
UserGroupMember existing = userGroupMemberDao.findForGroupAndUser(userGroup, user);
if (existing != null)
return;
UserGroupMember groupMember = new UserGroupMember(userGroup, user);
userGroupMemberDao.save(groupMember);
}