     {
         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,

            }
        }
    }

    // navigationBar _UIBarBackground alpha
    var navBarBackgroundAlpha:CGFloat {
        get {
