A simple swift timer program that runs in Xcode Playground

LongRunning.swift

import UIKit

class MyClass {
    
    func startTimer() {
        NSTimer.scheduledTimerWithTimeInterval(2, target: self, selector: #selector(MyClass.onTimer(_:)), userInfo: nil, repeats: false)
    }
    
    @objc func onTimer(timer:NSTimer!) {
        print("Timer here")
    }
}

var anInstance = MyClass()

anInstance.startTimer()

CFRunLoopRun()