code: AtomSymbol resize(double scaleX, double scaleY) {
          Point2D center = element.getCenter();
          AffineTransform transform = new AffineTransform();
          transform.translate(center.getX(), center.getY());
          transform.scale(scaleX, scaleY);
          transform.translate(-center.getX(), -center.getY());
          return transform(transform);
      }
docs: Convenience function to resize an atom symbol.
  
  @param scaleX x-axis scaling
  @param scaleY y-axis scaling
  @return the resized symbol (new instance)