RxSwift ReplaySubject type

ReplaySubject.swift

    //disposeBag from memoy management
    let disposeBag = DisposeBag()
    //Create our ReplaySubject with a string type
    let subject = ReplaySubject<String>.create(bufferSize: 2)
   
    subject.on(.Next("A"))

    //New Subscription
    subject.subscribe {
        print($0)
        }
        .addDisposableTo(disposeBag)
    
    

    
    //emits
    subject.on(.Next("B"))
    subject.onNext("C") //onNext is a Convenience method equivalent to on(.Next(element: E))
    
    
    
    //New Subscription
    let secondSubscription = subject.subscribe {
        print("Second subscription:", $0)
    }
    //add it to the disposeBag
    secondSubscription.addDisposableTo(disposeBag)
    //emit
    subject.onNext("D")