class Test: UIButton {
    var test = 0
    
    override func addTarget(_ target: Any?, action: Selector, for controlEvents: UIControlEvents) {
        print("\(String(describing: target))")
        super.addTarget(target, action: action, for: controlEvents)
    }
}

class ViewController: UIViewController {
    let test: Test = {
        let b = Test(type: .system);
        b.addTarget(self, action: #selector(ViewController.changed), for: UIControlEvents.touchUpInside)
        return b
    }()
    
    @objc func changed() {
        print("Hello pressed!")
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        let s = self.test
        s.setTitle("Hello", for: .normal)
        s.frame = CGRect(x: 0, y: 0, width: 100, height: 100)
        self.view.addSubview(s)
    }
}