         super.viewWillAppear(animated)
 
         self.hideNavBar()
-        if let button = self.navigationItem.leftBarButtonItem {
+        
+        if let _ = self.navigationItem.leftBarButtonItem {
                self.navigationItem.leftBarButtonItem!.action = #selector(invokeCallbackCancelShowingNavBar)
         }
 

    }

    public func scrollViewDidScroll(_ scrollView: UIScrollView) {

        self.didScrollInTable(scrollView)
    }

    override open func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
    }

 }


    open override func viewDidLoad() {
        super.viewDidLoad()

        NotificationCenter.default.addObserver(self, selector: #selector(self.updateCoupon(_:)), name: NSNotification.Name(rawValue: "MPSDK_UpdateCoupon"), object: nil)

