                 return
         }
 
+        animating = true
         let duration = ZoomTransitioning.transitionDuration * (1.0 - interactiveProgress)
         UIView.animateWithDuration(
             duration,

                transitionContext.finishInteractiveTransition()
                transitionContext.completeTransition(true)
                self.transitionContext = nil
        })
    }



    func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailByGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return gestureRecognizer is UIScreenEdgePanGestureRecognizer
    }

    func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldReceiveTouch touch: UITouch) -> Bool {
        return !animating
    }
}

