getWrapperKey method
Implementation
@override
Future<String?> getWrapperKey(String url, {bool override = false}) {
if (_wrapperKey != null && !override) return Future.value(_wrapperKey);
final url = (html.document.window?.location as html.Location?)?.href;
final wrapperKey = url?.split('wrapper_key=').last;
_wrapperKey = wrapperKey;
return Future.value(wrapperKey);
}