function Animal(name) { this.name = name; } Animal.prototype.sayHello = function() { return 'Hello from ' + this.name; }; Animal.prototype.makeNoise = function() { return this.noise || <1>'<chirp>'; }; function Dog(name, breed) { this.name = name; this.breed = breed; this.noise = 'Woof!'; } Dog.prototype = new Animal(); Dog.prototype.sayExtendedHello = function() { return this.sayHello() + ', ' + this.breed; }; Dog.prototype.bark = function() { return this.noise; }; module.exports = { Animal: Animal, Dog: Dog, };