code: public void appendToLastMessage(CommsByteBuffer msgBuffer, boolean lastChunk)
     {
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.entry(this, tc, "appendToLastMessage",
                                             new Object[]{msgBuffer, lastChunk});
  
        synchronized (this)
        {
           // Get the last queue data from the queue
           QueueData queueData = queue.getLast();
           queueData.addSlice(msgBuffer, lastChunk);
  
           // If this is the last chunk, update the counters to indicate a complete message has now
           // been received
           if (lastChunk)
           {
              notifyMessageReceived(queueData.isLastInBatch());
           }
        }
  
        if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) SibTr.debug(this, tc, "Append has completed: " + this);
  
        if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled()) SibTr.exit(this, tc, "appendToLastMessage");
     }
docs: This method is called when a middle or final chunk of a message has been received by the
  proxy queue. In this case we should append the chunk to those already collected and if this
  is the last chunk we perform the processing that would normally be done when a full message
  is received.
  
  @see com.ibm.ws.sib.comms.client.proxyqueue.queue.Queue#appendToLastMessage(com.ibm.ws.sib.comms.common.CommsByteBuffer, boolean)