code: public synchronized void newGuessInStream(long tick) throws SIResourceException
    {
  
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.entry(this, tc, "newGuessInStream", new Object[] { Long.valueOf(tick),
            Boolean.valueOf(containsGuesses),
            Long.valueOf(sendWindow),
            Long.valueOf(totalMessages),
            Long.valueOf(firstMsgOutsideWindow)});
      
      // If this is the first guess in the stream 
      if( !containsGuesses)
      { 
        containsGuesses=true;  
        if( sendWindow > totalMessages )
        {
          sendWindow = totalMessages;
          persistSendWindow(sendWindow, null);  
          firstMsgOutsideWindow = tick; 
        }  
      }
           
      if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
        SibTr.exit(tc, "newGuessInStream", new Object[] {Boolean.valueOf(containsGuesses),
            Long.valueOf(sendWindow),
            Long.valueOf(firstMsgOutsideWindow)});
    }
docs: Also called by writeUncomitted when a guess is written into the stream