code: public void setRolloverPeriod(Duration period)
    {
      _rolloverPeriod = period.toMillis();
  
      if (_rolloverPeriod > 0) {
        _rolloverPeriod += 3600000L - 1;
        _rolloverPeriod -= _rolloverPeriod % 3600000L;
      }
      else
        _rolloverPeriod = Integer.MAX_VALUE; // Period.INFINITE;
    }
docs: Sets the log rollover period, rounded up to the nearest hour.
  
  @param period the new rollover period in milliseconds.