docs: @Override
    public void setEndTime(final long timestamp) {
      if (timestamp < 0 || ((timestamp & Const.SECOND_MASK) != 0 && 
          timestamp > 9999999999999L)) {
        throw new IllegalArgumentException("Invalid timestamp: " + timestamp);
      } else if (start_time != UNSET && timestamp <= getStartTime()) {
        throw new IllegalArgumentException("new end time (" + timestamp
            + ") is less than or equal to start time: " + getStartTime());
      }
      end_time = timestamp;
    }