static void updateServerSideMetrics(ScanMetrics scanMetrics, ScanResponse response) {
    if (scanMetrics == null || response == null || !response.hasScanMetrics()) {
      return;
    }
    ResponseConverter.getScanMetrics(response).forEach(scanMetrics::addToCounter);
  }
Use the scan metrics returned by the server to add to the identically named counters in the
client side metrics. If a counter does not exist with the same name as the server side metric,
the attempt to increase the counter will fail.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java