In support to blog post

RetainCycle2.swift

class Person {
    let name: String
    init(name: String) { 
      self.name = name 
    }
    
    deinit { 
        print("\(name) is being deinitialized") 
    }
}

class Apartment {
    let number: Int
    var person: Person?
    init(number: Int) { 
      self.number = number 
    }
    
    deinit { 
        print("Apartment \(number) is being deinitialized") 
    }
}

var person: Person? = Person(name: "John Doe")
var apartment: Apartment? = Apartment(number: 123)
apartment.person = person

person = nil

// output:
//