In support to blog post

RetainCycle4.swift

class Person {
    let name: String
    var apartment: Apartment?
    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") 
    }
}