//ECMAScript 6 feature
class Phone {
    constructor(model) {
        this.model = model
    }
}

class Employee {
    constructor(firstName, lastName, phone) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.phone = phone;
    }
}

let nokiaPhone = new Phone("Nokia 6610");

let kim = new Employee("Victorya", "Kim",
    new Phone("iPhone 11 Pro"));

console.log(kim.phone.model);