public void incSumStats(String sumKey) {
        if (isStopped()) {
            return;
        }
        statsUnits[getWriteIndex()].incSumStats(sumKey);
    }
add summary statistic items

@param sumKey the summary key
inlong-dataproxy/dataproxy-source/src/main/java/org/apache/inlong/dataproxy/metrics/stats/MonitorStats.java