Answers for "flutter_facebook_auth Unhandled Exception: MissingPluginException(No implementation found for method getAll on channel plugins.flutter.io/shared_preferences"

MissingPluginException(No implementation found for method getAll on channel plugins.flutter.io/shared_preferences)

inside main.dart before start app add below code

SharedPreferences.setMockInitialValues({});

for reason:
https://stackoverflow.com/questions/50687801/flutter-unhandled-exception-missingpluginexceptionno-implementation-found-for