 private var flickerNumberFormatterKey : Void?
 private var flickerTimerKey : Void?
 
-public extension UILabel {
+extension UILabel {
     /// The intermediate number, it's private variable. Extend property use the runtime feature.
     public var fn_number: NSNumber? {
         get {

            return
        }
        
        //limit duration is postive number and it is large than 0.3
        var durationTime : TimeInterval = fabs(duration) < 0.3 ? 0.3 : fabs(duration)
        
        self.fn_timer?.invalidate()
        

}


