private void removeOrphanedResourceGroupMembers() {
   final Collection<GroupMember> members = resourceGroupManager.getOrphanedResourceGroupMembers();
   if (!members.isEmpty()) {
     log.info("cleaning up " + members.size() + " orphaned group members");
   }
   for (final GroupMember m : members) {
     resourceGroupManager.removeGroupMember(m);
   }
 }