@Override
    public boolean combine(Metrics metrics) {
        this.isCalculated = false;

        PercentileMetrics percentileMetrics = (PercentileMetrics) metrics;
        this.dataset.append(percentileMetrics.dataset);
        return true;
    }
Percentile is a better implementation than deprecated PxxMetrics in older releases.
This could calculate the multiple P50/75/90/95/99 values once for all.

@since 7.0.0
Deprecated since 10.0.0, use {@link PercentileMetrics2} instead.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/metrics/PercentileMetrics.java