medium-7.js

function Base() {}
Base.prototype.foo = function() {return 'foo in Base';};

function Child() {}
Object.setPrototypeOf(Child, Base);
Object.setPrototypeOf(Child.prototype, Base.prototype);

const homeObject = Child.prototype;
Child.prototype.foo = function() {return 'foo in Child';};
Child.prototype.bar = function() {
    // super.foo();
    return Object.getPrototypeOf(homeObject).foo.call(this);
};

const c = new Child;
console.log(c.foo()); // foo in Child
console.log(c.bar()); // foo in Base