constructor magic

package
{
    import flash.display.Sprite;

    public class HelloWorld extends Sprite
    {
        public function HelloWorld()
        {
            new Foo();
            
            (Foo as Object).constructor = function()
            {
                trace("world");
            }
            
            new (Foo as Object).constructor;
        }
    }


}

class Foo extends Object
{
    public function Foo()
    {
        trace("hello");
    }
}