@Override
    public void in(Metrics metrics) {
        if (Objects.nonNull(hourPersistenceWorker)) {
            hourPersistenceWorker.in(metrics.toHour());
        }
        if (Objects.nonNull(dayPersistenceWorker)) {
            dayPersistenceWorker.in(metrics.toDay());
        }
    }
Use the {@link Metrics#toHour()} and {@link Metrics#toDay()}to clone a new metrics instance then process the
downsampling. Then forward the data to different works of different precisions for another round
aggregation/merging.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/MetricsTransWorker.java