code: public TransactionQueueData add(TransactionQueueData data) {
          return new TransactionQueueData
              (null,
               Math.min(mSnapshotStart, data.mSnapshotStart),
               Math.max(mSnapshotEnd, data.mSnapshotEnd),
               mQueueSize + data.mQueueSize,
               mThreadCount + data.mThreadCount,
               mServicingCount + data.mServicingCount,
               Math.max(mPeakQueueSize, data.mPeakQueueSize),
               Math.max(mPeakThreadCount, data.mPeakThreadCount),
               Math.max(mPeakServicingCount, data.mPeakServicingCount),
               mTotalEnqueueAttempts + data.mTotalEnqueueAttempts,
               mTotalEnqueued + data.mTotalEnqueued,
               mTotalServiced + data.mTotalServiced,
               mTotalExpired + data.mTotalExpired,
               mTotalServiceExceptions + data.mTotalServiceExceptions,
               mTotalUncaughtExceptions + data.mTotalUncaughtExceptions,
               mTotalQueueDuration + data.mTotalQueueDuration,
               mTotalServiceDuration + data.mTotalServiceDuration
               );
      }
docs: Adds TransactionQueueData to another.