private void setupSearchCluster(ContentSearchCluster csc, ModelElement element, DeployLogger logger) {
            ContentSearch search = DomContentSearchBuilder.build(element);
            Double visibilityDelay = search.getVisibilityDelay();
            if (visibilityDelay != null) {
                csc.setVisibilityDelay(visibilityDelay);
            }
            IndexedSearchCluster sc = csc.getSearchCluster();
            if (sc != null) {
                setupIndexedCluster(sc, search, element, logger);
            }
        }
The admin model of this system or null if none (which only happens in tests)
config-model/src/main/java/com/yahoo/vespa/model/content/cluster/ContentCluster.java