public void scanWindowValues(Consumer<LinkedList<Map<String, Metrics>>> scanFunction) {
            lock.lock();
            try {
                scanFunction.accept(values);
            } finally {
                lock.unlock();
            }
        }
A metrics window, based on AlarmRule#period. This window slides with time, just keeps the recent N(period)
buckets.
oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/RunningRule.java