build method Null safety

Implementation

@override
Widget build(BuildContext context) {
  return MultiRepositoryProvider(
    providers: [
      RepositoryProvider.value(value: reddit),
      RepositoryProvider.value(value: auth),
      RepositoryProvider.value(value: user),
      RepositoryProvider.value(value: posts),
      RepositoryProvider.value(value: settings),
      RepositoryProvider.value(value: ThemeData(
        toggleableActiveColor: Color(0xFFF26875),
        colorScheme: ColorScheme.fromSwatch(
          primarySwatch: MaterialColor(0xFFF26875, {
            50: Color.fromRGBO(136,14,79, .1),
            100: Color.fromRGBO(136,14,79, .2),
            200: Color.fromRGBO(136,14,79, .3),
            300: Color.fromRGBO(136,14,79, .4),
            400: Color.fromRGBO(136,14,79, .5),
            500: Color.fromRGBO(136,14,79, .6),
            600: Color.fromRGBO(136,14,79, .7),
            700: Color.fromRGBO(136,14,79, .8),
            800: Color.fromRGBO(136,14,79, .9),
            900: Color.fromRGBO(136,14,79, 1),
          })
        )
      ))
    ],
    child: BlocProvider(
      create: (ctx) => AuthenticationBloc(auth: ctx.read(), user: ctx.read()),
      child: Builder(
        builder: (ctx) => MaterialApp(
          title: "Soreo",
          theme: ctx.read(),
          home: Scaffold(
            appBar: AppBarView(),
            body: const PostListPage()
          )
        )
      )
    )
  );
}