import UIKit

class MainViewController: UIViewController {


  func runScenario() {
    let user = User(name: "John")
    let iPhone = Phone(model: "iPhone Xs")
    user.add(phone: iPhone)
  }








  override func viewDidLoad() {
    super.viewDidLoad()
    runScenario()

  }




  class Phone {
    let model: String
    var owner: User?
    init(model: String) {
      self.model = model
      print("Phone \(model) was initialized")
    }

    deinit {
      print("Deallocating phone named: \(model)")
    }
  }

  class User {
    let name: String
    private(set) var phones: [Phone] = []

    func add(phone: Phone) {
      phones.append(phone)
      phone.owner = self
    }

    init(name: String) {
      self.name = name
      print("User \(name) was initialized")
    }

    deinit {
      print("Deallocating user named: \(name)")
    }
  }




}