code: int loadFSEdits(EditLogInputStream edits, long lastAppliedTxId) 
    throws IOException {
      long startTime = now();
      this.lastAppliedTxId = lastAppliedTxId;
      int numEdits = loadFSEdits(edits, true);
      FSImage.LOG.info("Edits file " + edits.toString() 
          + " of size: " + edits.length() + ", # of edits: " + numEdits 
          + " loaded in: " + (now()-startTime)/1000 + " seconds.");
      return numEdits;
    }
docs: Load an edit log, and apply the changes to the in-memory structure
  This is where we apply edits that we've been writing to disk all
  along.