public void setClusters(Set<String> clusters) {
        synchronized (mutex) {
            this.containerHasClusters = clusters.size() > 0;
            for (Iterator<String> i = clusterStatus.keySet().iterator(); i.hasNext(); ) {
                String existingCluster = i.next();
                if ( ! clusters.contains(existingCluster))
                    i.remove(); // forget clusters which was configured away
            }
        }
    }
Sets the current clusters of this container
container-core/src/main/java/com/yahoo/container/handler/ClustersStatus.java