private double skewReductionByRemoving(Node node, Node fromHost, HostCapacity capacity) {
        NodeResources freeHostCapacity = capacity.unusedCapacityOf(fromHost).justNumbers();
        double skewBefore = Node.skew(fromHost.flavor().resources(), freeHostCapacity);
        double skewAfter = Node.skew(fromHost.flavor().resources(), freeHostCapacity.add(node.flavor().resources().justNumbers()));
        return skewBefore - skewAfter;
    }
We do this here rather than in MetricsReporter because it is expensive and frequent updates are unnecessary
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/Rebalancer.java