private static NodeResources versioned(ClusterSpec spec, Map<Version, NodeResources> resources) {
        return requireNonNull(new TreeMap<>(resources).floorEntry(spec.vespaVersion()),
                              "no default resources applicable for " + spec + " among: " + resources)
                       .getValue();
    }
Returns the resources for the newest version not newer than that requested in the cluster spec.
config-provisioning/src/main/java/com/yahoo/config/provision/CapacityPolicies.java