code: public static <S> PAreaSizeBI<S> toPAreaSizeBI(final AreaSizeBI a)
    {
      Objects.requireNonNull(a, "area size");
      return PAreaSizeBI.of(a.sizeX(), a.sizeY());
    }
docs: Convert an area size.
  
  @param a   The area size
  @param <S> A phantom type parameter indicating the coordinate space of the
  area size
  
  @return An area size