code: @Override
      public void merge(String streamSegmentName, long dataLength, int numOfEvents, long txnCreationTime) {
          getDynamicLogger().incCounterValue(SEGMENT_WRITE_BYTES, dataLength, segmentTags(streamSegmentName));
          getDynamicLogger().incCounterValue(SEGMENT_WRITE_EVENTS, numOfEvents, segmentTags(streamSegmentName));
  
          SegmentAggregates aggregates = getSegmentAggregate(streamSegmentName);
          if (aggregates != null && aggregates.updateTx(dataLength, numOfEvents, txnCreationTime)) {
              report(streamSegmentName, aggregates);
          }
      }
docs: Method called with txn stats whenever a txn is committed.
  
  @param streamSegmentName parent segment name
  @param dataLength        length of data written in txn
  @param numOfEvents       number of events written in txn
  @param txnCreationTime   time when txn was created