class LspTest
{
	private static Rectangle getNewRectangle()
	{
		// it can be an object returned by some factory ... 
		return new Square();
	}

	public static void main (String args[])
	{
		Rectangle r = LspTest.getNewRectangle();
        
		r.setWidth(5);
		r.setHeight(10);
// user knows that r it's a rectangle. It assumes that he's //able to set the width and height as for the base class

		System.out.println(r.getArea());
// now he's surprised to see that the area is 100 instead of 50.
	}
}