docs: public static byte[] rowKeyFromTSUID(final TSDB tsdb, final byte[] tsuid, 
        final long timestamp) {
      if (tsuid.length < tsdb.metrics.width()) {
        throw new IllegalArgumentException("TSUID appears to be missing the metric");
      }
      final long base_time;
      if ((timestamp & Const.SECOND_MASK) != 0) {
        // drop the ms timestamp to seconds to calculate the base timestamp
        base_time = ((timestamp / 1000) - 
            ((timestamp / 1000) % Const.MAX_TIMESPAN));
      } else {
        base_time = (timestamp - (timestamp % Const.MAX_TIMESPAN));
      }
      final byte[] row = 
          new byte[Const.SALT_WIDTH() + tsuid.length + Const.TIMESTAMP_BYTES];
      System.arraycopy(tsuid, 0, row, Const.SALT_WIDTH(), tsdb.metrics.width());
      Bytes.setInt(row, (int) base_time, Const.SALT_WIDTH() + tsdb.metrics.width());
      System.arraycopy(tsuid, tsdb.metrics.width(), row, 
          Const.SALT_WIDTH() + tsdb.metrics.width() + Const.TIMESTAMP_BYTES, 
          tsuid.length - tsdb.metrics.width());
      RowKey.prefixKeyWithSalt(row);
      return row;
    }