public class Main {

    public static void main(String[] args) {
        Bar bar = new Bar();
        bar.doSomething();
    }
}

class Foo {
    public Foo() {
        doSomething();
    }

    public void doSomething() {
        System.out.println("Do something important!");
    }
}

class Bar extends Foo {
    public void doSomething() {
        System.out.println("YOLO!");
        Zoom zoom = new Zoom(this);
    }
}

class Zoom {
    public Zoom(Bar bar) {
        bar.doSomething();
    }
}