All the sources codes "Joke"page 10

// @todo: nothing to do here

//--------------------------------------------------------------------------
    //
    //  Notes: Child management
    //
    //--------------------------------------------------------------------------

    /*

 Although at the level of a Flash DisplayObjectContainer, all
        children are equal, in a Flex Container some children are "more
        equal than others". (George Orwell, "Animal Farm")
....
*/

double penetration;    // ouch