 
 
 ///  An instance of `WebViewController` displays interactive web content.
-public final class WebViewController: UIViewController {
+public class WebViewController: UIViewController {
 
     // MARK: Properties
 

        self.init(urlRequest: NSURLRequest(URL: url))
    }

    public required init(coder aDecoder: NSCoder) {
        self.configuration = WKWebViewConfiguration()
        self.urlRequest = NSURLRequest(URL: NSURL(string: "")!)

                }

            case EstimatedProgressKeyPath:
                let completed = webView.estimatedProgress == 1.0
                progressBar.setProgress(completed ? 0.0 : Float(webView.estimatedProgress), animated: !completed)
                UIApplication.sharedApplication().networkActivityIndicatorVisible = !completed

            default: break
