docs: public static long[] interleaveBits(long[] coords, int iter) {
      final int numdim = coords.length;
      final long[] bitset = BitsUtil.zero(numdim);
      // convert longValues into zValues
      final long mask = 1L << 63 - iter;
      for(int dim = 0; dim < numdim; dim++) {
        if((coords[dim] & mask) != 0) {
          BitsUtil.setI(bitset, dim);
        }
      }
      return bitset;
    }