code: public Space subspace(Point<Integer> center) {
      Space		result;
      SpaceDimension[]	dimensions;
      int		i;
  
      dimensions = new SpaceDimension[dimensions()];
      for (i = 0; i < dimensions.length; i++)
        dimensions[i] = getDimension(i).subdimension(
          center.getValue(i) - 1, center.getValue(i) + 1);
  
      result = new Space(dimensions);
  
      return result;
    }
docs: Returns a subspace around the given point, with just one more
  neighbor left and right on each dimension.
  
  @param center	the center of the new "universe" ;-)
  @return		the new space