docs: protected void synchronizeGroupMembersOnDelete(IEntityGroup group) throws GroupsException {
          GroupMemberImpl gmi = null;
  
          for (Iterator it = group.getChildren().iterator(); it.hasNext(); ) {
              gmi = (GroupMemberImpl) it.next();
              gmi.invalidateInParentGroupsCache(Collections.singleton((IGroupMember) gmi));
              if (cacheInUse()) {
                  cacheUpdate(gmi);
              }
          }
      }