class ConnectMetrics {

    public MetricGroup group(String groupName, String... tagKeyValues) {
        MetricGroupId groupId = groupId(groupName, tagKeyValues);
        MetricGroup group = groupsByName.get(groupId);
        if (group == null) {
            group = new MetricGroup(groupId);
            MetricGroup previous = groupsByName.putIfAbsent(groupId, group);
            if (previous != null)
                group = previous;
        }
        return group;
    }

    public  ConnectMetrics(String workerId, WorkerConfig config, Time time, String clusterId);

}