var WAIT_TIME : Int = 2
var TIMEOUT_TIME : Int = 5

let pub = PassthroughSubject<String, Never>()

let cancellable = pub
    .timeout(.seconds(TIMEOUT_TIME), scheduler: DispatchQueue.main, options: nil, customError:nil)
    .sink(
          receiveCompletion: { print ("completion: \($0) at \(Date())") },
          receiveValue: { print ("value: \($0) at \(Date())") }
     )

DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(WAIT_TIME),
                              execute: {
                                pub.send("Some data - sent after a delay of \(WAIT_TIME) seconds")
                              })