private Map<ClusterSpec.Id, NodeList> nodesByCluster(NodeList applicationNodes) {
        return applicationNodes.groupingBy(n -> n.allocation().get().membership().cluster().id());
    }
Check if the last scaling event for this cluster has completed and if so record it in the returned instance
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainer.java