class WindowedMapGauge extends Gauge<Map<String,Object>> {

    public Windows getWindowStartTimes(long tsMs) {
        long activeStartMs = tsMs/windowDurationMs * windowDurationMs;
        return new Windows(activeStartMs, activeStartMs - windowDurationMs);
    }

    public  WindowedMapGauge(String name, long windowDurationMs, BiFunction<V,V,V> mergeFunc);
    public  WindowedMapGauge(String name, long windowDurationMs, BiFunction<V,V,V> mergeFunc, Clock clock);

}