docs: static long extractIntegerValue(final byte[] values,
                                    final int value_idx,
                                    final byte flags) {
      switch (flags & Const.LENGTH_MASK) {
        case 7: return Bytes.getLong(values, value_idx);
        case 3: return Bytes.getInt(values, value_idx);
        case 1: return Bytes.getShort(values, value_idx);
        case 0: return values[value_idx];
      }
      throw new IllegalDataException("Integer value @ " + value_idx
                                     + " not on 8/4/2/1 bytes in "
                                     + Arrays.toString(values));
    }