Error: Method not found: 'webOnlySetPluginHandler'.

```
import 'package:flutter/material.dart';
import 'package:flutter_web_plugins/flutter_web_plugins.dart';
import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';

class pdfView extends StatelessWidget {
@override
Widget build(BuildContext context) {
return WebviewScaffold(
appBar: AppBar(
title: Text("pdf"),
),
url: "http://www.nie.ac.in/wp-content/uploads/2015/05/I-Sc-Engg.-II-year-2019-20.pdf",
allowFileURLs: true,
withJavascript: true,
withZoom: true,
initialChild: Center(
child: CircularProgressIndicator(),
),
);
}
}

```

Start by reproducing the error with the shown imports and the pdfView widget's WebviewScaffold usage. Then inspect the flutter_web_plugins and flutter_webview_plugin integration to determine why webOnlySetPluginHandler is unavailable; done means the example runs without this method-not-found error.

Written by the indexing model from the issue text.