code: public TransportStats getStats() {
      long localFlowControlWindow =
          flowControlWindowReader == null ? -1 : flowControlWindowReader.read().localBytes;
      long remoteFlowControlWindow =
          flowControlWindowReader == null ? -1 : flowControlWindowReader.read().remoteBytes;
      return new TransportStats(
          streamsStarted,
          lastLocalStreamCreatedTimeNanos,
          lastRemoteStreamCreatedTimeNanos,
          streamsSucceeded,
          streamsFailed,
          messagesSent,
          messagesReceived.value(),
          keepAlivesSent,
          lastMessageSentTimeNanos,
          lastMessageReceivedTimeNanos,
          localFlowControlWindow,
          remoteFlowControlWindow);
    }
docs: Returns a read only set of current stats.