RxSwift Variable type

Variable.swift

do {
    
    let disposeBag = DisposeBag()
    let variable = Variable("A")
    
    variable.value = "B"
    
    variable.asObservable()
        .subscribe { print($0) }
        .addDisposableTo(disposeBag)
    
    variable.value = "C"
    
    variable.asObservable()
        .subscribe { print("Second subscription:", $0) }
        .addDisposableTo(disposeBag)
}