docs: public static ModifiableHyperBoundingBox unionTolerant(SpatialComparable mbr1, SpatialComparable mbr2) {
      if(mbr1 == null && mbr2 == null) {
        return null;
      }
      if(mbr1 == null) {
        // Clone - intentionally
        return new ModifiableHyperBoundingBox(mbr2);
      }
      if(mbr2 == null) {
        // Clone - intentionally
        return new ModifiableHyperBoundingBox(mbr1);
      }
      return union(mbr1, mbr2);
    }