     /* ====================================================================== */
     
     public let wkWebView: WKWebView = WKWebView()
+    
+    public var showNavigationProgress = true
     
     public var tintColor = UIColor(red: 0, green: 122/255, blue: 1, alpha: 1) {
         didSet { updateTintColors() }

        
        switch keyPath {
        case KVOKeyPath.estimatedProgress:
            guard navigationController?.progress < 1.0 else {
                navigationController?.finishProgress()
                return
            }
            navigationController?.setProgress(Float(wkWebView.estimatedProgress), animated: true)
            
        case KVOKeyPath.canGoBack:

}


extension KYWebViewController: WKNavigationDelegate {
    
    public func webView(webView: WKWebView, didFinishNavigation navigation: WKNavigation!) {
        guard showNavigationProgress else { return }
        navigationController?.finishProgress()
    }
    
    public func webView(webView: WKWebView, didFailNavigation navigation: WKNavigation!, withError error: NSError) {
        guard showNavigationProgress else { return }
        navigationController?.finishProgress()
    }
    
}


extension KYWebViewController: PageHistoryViewControllerDelegate {
    
    func pageHistoryViewController(
