             }
         }
     }
-    
+
     // navigationBar _UIBarBackground alpha
     var navBarBackgroundAlpha:CGFloat {
         get {

    {
        navigationBar.wr_setBackgroundColor(color: barTintColor)
    }
    
    fileprivate func setNeedsNavigationBarUpdate(barBackgroundAlpha: CGFloat)
    {
        navigationBar.wr_setBackgroundAlpha(alpha: barBackgroundAlpha)
    }
    
    fileprivate func setNeedsNavigationBarUpdate(tintColor: UIColor) {
        navigationBar.tintColor = tintColor
    }
    
    fileprivate func setNeedsNavigationBarUpdate(titleColor: UIColor) {
        navigationBar.titleTextAttributes = [NSForegroundColorAttributeName:titleColor]
    }

        }
    }
    
    // swizzling system method: _updateInteractiveTransition
    func wr_updateInteractiveTransition(_ percentComplete: CGFloat)
    {
        guard let topViewController = topViewController,
