docs: private long updateBaseTime(final long timestamp) {
      // We force the starting timestamp to be on a MAX_TIMESPAN boundary
      // so that all TSDs create rows with the same base time. Otherwise
      // we'd need to coordinate TSDs to avoid creating rows that cover
      // overlapping time periods.
      final long base_time = timestamp - (timestamp % Const.MAX_TIMESPAN);
      // Clone the row key since we're going to change it. We must clone it
      // because the HBase client may still hold a reference to it in its
      // internal datastructures.
      row = Arrays.copyOf(row, row.length);
      Bytes.setInt(row, (int) base_time, Const.SALT_WIDTH() + tsdb.metrics.width());
      RowKey.prefixKeyWithSalt(row); // in case the timestamp will be involved in
                                     // salting later
      tsdb.scheduleForCompaction(row, (int) base_time);
      return base_time;
    }