protected override void OnElementChanged(VisualElementChangedEventArgs e)
        {
            base.OnElementChanged(e);

            if (NativeView != null)
            {
                ((WKWebView)NativeView).AllowsBackForwardNavigationGestures = true;
                _progressObserver = NativeView.AddObserver("estimatedProgress", NSKeyValueObservingOptions.New, ProgressObserverAction);
                SetSource();
            }
        }