code: public void updateTime(String streamId, String name, long start, long end, int count, boolean mergeTopology) {
          if (start > 0 && count > 0) {
              AsmMetric existingMetric = findMetric(streamId, name, MetricType.HISTOGRAM, mergeTopology);
  
              if (existingMetric instanceof AsmHistogram) {
                  AsmHistogram histogram = (AsmHistogram) existingMetric;
                  if (histogram.okToUpdate(end)) {
                      long elapsed = ((end - start) * TimeUtils.US_PER_MS) / count;
                      if (elapsed >= 0) {
                          histogram.update(elapsed);
                          histogram.setLastUpdateTime(end);
                      }
                  }
              }
          }
      }
docs: almost the same implementation of above update, but improves performance for histograms