code: public void resetIndex(long index, long timestamp) {
      currentOperation = OperationType.COMMAND;
      operationIndex = index;
      currentIndex = index;
      currentTimestamp = timestamp;
      setCommitIndex(index);
      service.tick(new WallClockTimestamp(currentTimestamp));
    }
docs: Resets the current index to the given index and timestamp.
  
  @param index     the index to which to reset the current index
  @param timestamp the timestamp to which to reset the current timestamp