unwind segue performing by runtime issue

Question

Apple says about unwind(for:towards:) method (which called when an unwind segue transitions to a new view controller):

During the execution of an unwind segue, UIKit calls this method on any view controllers in the unwind path to give them an opportunity to reconfigure themselves.

ok. I tried to check this fact. in the example there are 4 view controllers each was pushed. So on the outermost view controller i touched unwind button (@ibaction unwind method was implemented in the root view controller (pink)). Each child is ViewController: UIViewController class. And navigation controller is custon NavigationControlllerClass with unwind(for:towrds) and dismiss methods overrode to print the have been called. But So. According to apple words unwind(for:towards:) have to be called 4 times on ViewController: UIViewController class, and 1 times on CustomNavitaionController class. But it has been called only once on Viewcontroller class and only once on CustomNavigationController class. Why so??? Apple says on any...(((

  class ViewController : UIViewController {

@IBAction func doUnwind(_ sender:UIStoryboardSegue) {
    
}

override func allowedChildrenForUnwinding(from source: UIStoryboardUnwindSegueSource) -> [UIViewController] {
    let result = super.allowedChildrenForUnwinding(from: source)
    print("\(self) \(#function) \(result)")
    return result
}

override func unwind(for unwindSegue: UIStoryboardSegue, towards subsequentVC: UIViewController) {
    print("\(self)  \(subsequentVC)")
    super.unwind(for: unwindSegue, towards: subsequentVC)
}

override func canPerformUnwindSegueAction(_ action: Selector, from fromViewController: UIViewController, sender: Any?) -> Bool {
    var result = super.canPerformUnwindSegueAction(action, from: fromViewController, sender: sender)
    return result
}

override func dismiss(animated: Bool, completion: (() -> Void)?) {
    print("\(self) \(#function)")
    super.dismiss(animated:animated, completion: completion)
}

override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
    let result = super.shouldPerformSegue(withIdentifier: identifier, sender: sender)
    if identifier == "unwind" {
        print("\(self) \(#function) \(result)")
    }
    return result
}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "unwind" {
        print("\(self) \(#function)")
    }
}    
}





class MyNavController : UINavigationController {

override func allowedChildrenForUnwinding(from source: UIStoryboardUnwindSegueSource) -> [UIViewController] {
    let result = super.allowedChildrenForUnwinding(from: source)
    print("\(type(of:self)) \(#function) \(result)")
    return result
}

override func unwind(for unwindSegue: UIStoryboardSegue, towards subsequentVC: UIViewController) {
    print("\(type(of:self)) \(#function) \(subsequentVC)")
    super.unwind(for: unwindSegue, towards: subsequentVC)
}

override func canPerformUnwindSegueAction(_ action: Selector, from fromViewController: UIViewController, sender: Any?) -> Bool {
    let result = super.canPerformUnwindSegueAction(action, from: fromViewController, sender: sender)
    print("\(type(of:self)) \(#function) \(action) \(result)")
    return result
}

override func dismiss(animated: Bool, completion: (() -> Void)?) {
    print("\(type(of:self)) \(#function)")
    super.dismiss(animated:animated, completion: completion)
}

override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
    let result = super.shouldPerformSegue(withIdentifier: identifier, sender: sender)
    if identifier == "unwind" {
        print("\(type(of:self)) \(#function) \(result)")
    }
    return result
}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "unwind" {
        print("\(type(of:self)) \(#function)")
    }
}

override func popToViewController(_ viewController: UIViewController, animated: Bool) -> [UIViewController]? {
    print("\(type(of:self)) \(#function) \(viewController)")
    return super.popToViewController(viewController, animated:animated)
}    
 }