class Swizzle: NSObject {    override class func load() {        UIButton.xxx_swizzleSendAction()    }}extension UIButton {    class func xxx_swizzleSendAction() {        struct xxx_swizzleToken {            static var onceToken : dispatch_once_t = 0        }        dispatch_once(&xxx_swizzleToken.onceToken, { () -> Void in            let cls : AnyClass! = UIButton.self            let originalSelector = Selector("sendAction:to:forEvent:")            let swizzledSelector = Selector("xxx_sendAction:to:forEvent:")            let originalMethod = class_getInstanceMethod(cls, originalSelector)            let swizzledMethod = class_getInstanceMethod(cls, swizzledSelector)            method_exchangeImplementations(originalMethod, swizzledMethod)                    })    }    public  func xxx_sendAction(action : Selector, to : AnyObject!, forEvent : UIEvent!) {        struct xxx_buttonTapCount {            static var count : Int = 0        }        xxx_buttonTapCount.count += 1        println(xxx_buttonTapCount.count)        xxx_sendAction(action, to: to, forEvent: forEvent)    }}