         return animateTransition(for: presenting)(transitionContext)
     }
     
-    func animateTransition(for presenting: Bool) -> AnimateTransitionHandler {
+    //MARK: - Private
+    
+    private func animateTransition(for presenting: Bool) -> AnimateTransitionHandler {
         return presenting ? show : dismiss
     }
     


extension SlideTransitionAnimator: UIViewControllerAnimatedTransitioning {
    
    typealias AnimateTransitionHandler = (UIViewControllerContextTransitioning) -> ()
    
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return duration

        }
    }
    
    func center() {
        view.frame.origin = .zero
    }
    
