class MetricName implements Comparable<MetricName> {

    public MetricName tag(Map<String, String> add) {
        final Map<String, String> tags = new HashMap<String, String>(add);
        tags.putAll(this.tags);
        return new MetricName(key, tags, level);
    }

    public  MetricName();
    public  MetricName(String key);
    public  MetricName(String key, Map<String, String> tags);
    public  MetricName(String key, MetricLevel level);
    public  MetricName(String key, Map<String, String> tags, MetricLevel level);

}