private boolean changesConfiguredNodeSet(Collection<ConfiguredNode> newNodes) {
        if (newNodes.size() != cluster.getConfiguredNodes().size()) return true;
        if (! cluster.getConfiguredNodes().values().containsAll(newNodes)) return true;

        // Check retirement changes
        for (ConfiguredNode node : newNodes) {
            if (node.retired() != cluster.getConfiguredNodes().get(node.index()).retired()) {
                return true;
            }
        }

        return false;
    }
Called when all distributors have acked newest cluster state version.
clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java