code: public void defrag() throws IOException {
      OLogManager.instance().debug(this, "Starting to defragment the segment %s of size=%d and filled=%d", file, file.getFileSize(),
          file.getFilledUpTo());
  
      OLogManager.instance().debug(this, "Defragmentation ended for segment %s. Current size=%d and filled=%d", file,
          file.getFileSize(), file.getFilledUpTo());
    }
docs: TODO Check values removing dirty entries (equals to -1)