Pasted

class Engine {
 }
 class Auto {
    engine: Engine;
     constructor(engine: Engine) {
        this.engine = engine;
    }
}
 class Truck extends Auto {
    fourByFour: boolean;
     constructor(engine: Engine, fourByFour: boolean) {
        super(engine);
        this.fourByFour = fourByFour;
    }
}