/**
  * Get the Sum of all the stats that are watched, for all the stats added with add() since the
  * creation of this <tt>HammerSummaryStats</tt>
  *
  * @return The Sum of all the stats in JSON.
  */
 public String getAggregateSumJSON() {
   String str =
       String.format(
           FakeUserStats.jsonMediaStreamStatsTemplate,
           -1, // ssrc not needed here
           aggregateDownloadJitterMs.getSum(),
           aggregateDownloadPercentLoss.getSum(),
           aggregateDownloadRateKiloBitPerSec.getSum(),
           aggregateJitterBufferDelayMs.getSum(),
           aggregateJitterBufferDelayPackets.getSum(),
           aggregateNbDiscarded.getSum(),
           aggregateNbDiscardedFull.getSum(),
           aggregateNbDiscardedLate.getSum(),
           aggregateNbDiscardedReset.getSum(),
           aggregateNbDiscardedShrink.getSum(),
           aggregateNbFec.getSum(),
           aggregateNbPackets.getSum(),
           aggregateNbPacketsLost.getSum(),
           aggregateNbReceivedBytes.getSum(),
           aggregateNbSentBytes.getSum(),
           aggregatePacketQueueCountPackets.getSum(),
           aggregatePacketQueueSize.getSum(),
           aggregatePercentDiscarded.getSum(),
           aggregateRttMs.getSum(),
           aggregateUploadJitterMs.getSum(),
           aggregateUploadPercentLoss.getSum(),
           aggregateUploadRateKiloBitPerSec.getSum());
   return str;
 }