code: @Override
    @InService(PageServiceSync.class)
    public void afterDataFlush(PageServiceImpl tableService,
                               int sequenceFlush)
    {
      super.afterDataFlush(tableService, sequenceFlush);
      
      sweepStub(tableService);
    }
docs: Callback after the data has been written to the mmap, which allows for
  reads (but not necessarily fsynced.)