     }
 }
 
-//MARK: interaction
 extension NavigationTransitionController : UIViewControllerInteractiveTransitioning
 {
     func startInteractiveTransition(_ transitionContext: UIViewControllerContextTransitioning)

    }
}

//MARK: delegate
extension NavigationTransitionController : UINavigationControllerDelegate
{
    func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning?

    }
}

extension NavigationTransitionController : UIViewControllerAnimatedTransitioning
{
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval
