docs: public boolean extend(SpatialComparable obj) {
      final int dim = min.length;
      assert (obj.getDimensionality() == dim);
      boolean extended = false;
      for(int i = 0; i < dim; i++) {
        final double omin = obj.getMin(i);
        final double omax = obj.getMax(i);
        if(omin < min[i]) {
          min[i] = omin;
          extended = true;
        }
        if(omax > max[i]) {
          max[i] = omax;
          extended = true;
        }
      }
      return extended;
    }