 private let formatName = "format"
 private let frequency = 1.0/30.0
 
-public extension UILabel {
+extension UILabel {
      /**
      Flicker a number without other effects.
      

}






private var flickerNumberFormatterKey : Void?
private var flickerTimerKey : Void?

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