使用swift如何使用手势识别swipe和pan

Question

了解到两个手势swipe和pan同时存在的时候，会默认把手势识别为pan，我现在想做到区别swipe和pan，两个事件分别触发不同的action改如何做
我是用了代理，gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool会同时识别两个手势
但不能只识别一个手势，没有看懂gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailByGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool和gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRequiredToFailByGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool的区别？求解答！