Quiz on Using Inheritance

The add() method of Set returns the instance of Set with the added element. Let’s change

const set = new FunctionalSet(['Jack', 'Jill', 'Tom', 'Jerry']);

to:

const set = new FunctionalSet(['Jack', 'Jill', 'Tom', 'Jerry']) .add('Bill');

What change do we have to make in the FunctionalSet class to make the add() function work for this modified code?

class FunctionalSet extends Set {
}