BehaviorSubject.swift

let subject = BehaviorSubject<String>.init(value: "Init Value")

subject.onNext("Is anyone listening?")

let subcription1 = subject.subscribe { event in
    print("1) \(event)")
}

let subcription2 = subject.subscribe { event in
    print("2) \(event)")
}

subject.onNext("Hello")
subject.onCompleted()
subject.onNext("Is alive?")


<Output>
1) next(Is anyone listening?)
2) next(Is anyone listening?)
1) next(Hello)
2) next(Hello)
1) completed
2) completed