docs: public boolean updateSourceStream(MessageItem msg, boolean rollback) throws SIResourceException
    {
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.entry(tc, "updateSourceStream", new Object[] { msg, new Boolean(rollback)});
        
      
      // return flag indicating whether the message can be sent downstream
      boolean sendMessage = true;    
  
      // Write the value message to the stream
      // This will also write a range of Completed ticks between
      // the previous Value tick and the new one
      sendMessage = sourceStreamManager.updateSourceStream(msg, rollback);
          
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.exit(tc, "updateSourceStream");
        
      return sendMessage;    
    }