private ZookeeperServerConfig.Server.Builder getZkServer(ConfigServer server, int id) {
        ZookeeperServerConfig.Server.Builder builder = new ZookeeperServerConfig.Server.Builder();
        builder.hostname(server.hostName);
        builder.id(id);
        return builder;
    }
Represents a config server cluster.

@author Ulf Lilleengen
config-model/src/main/java/com/yahoo/vespa/model/container/configserver/ConfigserverCluster.java