private List<NodeTimeseries> keepGenerationAfterWarmup(List<NodeTimeseries> timeseries, long currentGeneration) {
        return timeseries.stream()
                         .map(nodeTimeseries -> nodeTimeseries.keepGenerationAfterWarmup(currentGeneration,
                                                                                         clusterNodes.node(nodeTimeseries.hostname())))
                         .toList();
    }
Returns the "peak load" in this: Which is for each load dimension,
the average of the highest reading for that dimension on each node.
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/ClusterNodesTimeseries.java