private void addCluster(IndexedSearchCluster sc) {
        if (searchCluster != null) {
            throw new IllegalArgumentException("Duplicate indexed cluster '" + searchCluster.getClusterName() + "'");
        }
        searchCluster = sc;
    }
Whether the nodes of this cluster also hosts a container cluster in a hosted system
config-model/src/main/java/com/yahoo/vespa/model/content/ContentSearchCluster.java