private boolean hasClusterControllerComponent(Container container) {
            for (Object o : container.getComponents().getComponents())
                if (o instanceof ClusterControllerComponent) return true;
            return false;
        }
Returns of memory reserved on a host. Memory is reserved for the jvm if the cluster is combined
config-model/src/main/java/com/yahoo/vespa/model/content/cluster/ContentCluster.java