final TopologyViewImpl topology = new TopologyViewImpl();
final ClusterView localClusterView = clusterViewService.getClusterView();
final List<InstanceDescription> localInstances = localClusterView.getInstances();
topology.addInstances(localInstances);
Collection<InstanceDescription> attachedInstances = announcementRegistry
.listInstances(localClusterView);
topology.addInstances(attachedInstances);