如何关闭webview从关闭运行？了JavaFx

 Platform.runLater(() -> {
            WebView wv = new WebView();
            final WebEngine engine = wv.getEngine();
            fxpanel.setScene(new Scene(wv));
            engine.setJavaScriptEnabled(true);
            engine.load(Url);
        };
 Platform.runLater(() -> {
            WebView