http-server/src/main/java/io/airlift/http/server/HttpServerChannelListener.java
@Nullable
    private static DoubleSummaryStats processContentTimestamps(List<Long> contentTimestamps)
    {
        requireNonNull(contentTimestamps, "contentTimestamps is null");

        // no content (HTTP 204) or there was a single response chunk (so no interarrival time)
        if (contentTimestamps.size() == 0 || contentTimestamps.size() == 1) {
            return null;
        }

        DoubleSummaryStatistics statistics = new DoubleSummaryStatistics();
        long previousTimestamp = contentTimestamps.get(0);
        for (int i = 1; i < contentTimestamps.size(); i++) {
            long timestamp = contentTimestamps.get(i);
            statistics.accept(NANOSECONDS.toMillis(timestamp - previousTimestamp));
            previousTimestamp = timestamp;
        }
        return new DoubleSummaryStats(statistics);
    }
@Nullable
    private static DoubleSummaryStats processContentTimestamps(List<Long> contentTimestamps)
    {
        requireNonNull(contentTimestamps, "contentTimestamps is null");

        // no content (HTTP 204) or there was a single response chunk (so no interarrival time)
        if (contentTimestamps.size() == 0 || contentTimestamps.size() == 1) {
            return null;
        }

        DoubleSummaryStatistics statistics = new DoubleSummaryStatistics();
        long previousTimestamp = contentTimestamps.get(0);
        for (int i = 1; i < contentTimestamps.size(); i++) {
            long timestamp = contentTimestamps.get(i);
            statistics.accept(NANOSECONDS.toMillis(timestamp - previousTimestamp));
            previousTimestamp = timestamp;
        }
        return new DoubleSummaryStats(statistics);
    }
Calculate the summary statistics for the interarrival time of the onResponseContent callbacks.