docs: public static final int dimensionality(SpatialComparable o1, SpatialComparable o2) {
      final int dim1 = o1.getDimensionality(), dim2 = o2.getDimensionality();
      if(dim1 != dim2) {
        throw new IllegalArgumentException("Objects do not have the same dimensionality.");
      }
      return dim1;
    }