@Override
    public String toString() {
        return "BCP group info: " + queryRate + " q/s, " + growthRateHeadroom + " q/s headroom, " +
               cpuCostPerQuery + " CPU cost per q/s";
    }
Returns the average total cluster CPU cost per query of the other clusters in the group this belongs to.
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/applications/BcpGroupInfo.java