code: public boolean isFlushed(SIBUuid12 streamID)
    {
      //note that although it is true that this method is currently
      //equivalent to !hadStream(streamID), it may not always be true in
      //the future.
      if(streamSet == null) return true;
  
      return !streamID.equals(streamSet.getStreamID());
    }
docs: returns true if a given set of streams are flushed
  
  @param streamID