     var runJavaScriptAlertPanelWithMessage: LKRunJavaScriptAlertPanelWithMessage?
     var runJavaScriptConfirmPanelWithMessage: LKRunJavaScriptConfirmPanelWithMessage?
     var runJavaScriptTextInputPanelWithPrompt: LKRunJavaScriptTextInputPanelWithPrompt?
-    var shouldPreviewElement: LKShouldPreviewElement?
-    var previewingViewControllerForElement: LKPreviewingViewControllerForElement?
     var commitPreviewingViewController: LKCommitPreviewingViewController?
 }

        } else {
            completionHandler(nil)
        }
    }

    public func webView(_ webView: WKWebView, shouldPreviewElement elementInfo: WKPreviewElementInfo) -> Bool
    {
        return self.shouldPreviewElement?(webView, elementInfo) ?? true
    }

    public func webView(_ webView: WKWebView,
                        previewingViewControllerForElement elementInfo: WKPreviewElementInfo,
                        defaultActions previewActions: [WKPreviewActionItem]) -> UIViewController?
    {
        return self.previewingViewControllerForElement?(webView, elementInfo, previewActions)
    }

    public func webView(_ webView: WKWebView,

    (WKWebView, String, WKFrameInfo, ((Bool) -> Void)) -> Void
public typealias LKRunJavaScriptTextInputPanelWithPrompt =
    (WKWebView, String, String?, WKFrameInfo, ((String?) -> Void)) -> Void
public typealias LKCommitPreviewingViewController = (WKWebView, UIViewController) -> Void

// MARK: - WKNavigationDelegate
