/** {@inheritDoc} */
  @Override
  public int compareTo(GridClockDeltaVersion o) {
    int res = Long.compare(topVer, o.topVer);

    if (res == 0) res = Long.compare(ver, o.ver);

    return res;
  }
    /** {@inheritDoc} */
    @Override
    public int compareTo(CancelMessageId m) {
      int res = Long.compare(reqId, m.reqId);

      if (res == 0) res = m.nodeId.compareTo(nodeId);

      return res;
    }
 @Override
 public int compare(VisorLogFile f1, VisorLogFile f2) {
   return Long.compare(f2.lastModified(), f1.lastModified());
 }
 @Override
 public int compare(Event o1, Event o2) {
   return Long.compare(o1.localOrder(), o2.localOrder());
 }