synchronized IHistogramData getHourlyStores() {
   HSMWritesHourly entry = new HSMWritesHourly();
   entry.setCount(storeCount);
   entry.setDate(timestamp);
   entry.setSize(bytesStored);
   return entry;
 }
 private void update(HSMWritesHourly data) {
   storeCount += data.getCount();
   bytesStored += data.getSize();
 }