How to move a variable outside build?

How do I move a variable that uses a context outside of the build method so that it is created once?

class _EventListState extends State<EventList> {
  @override
  Widget build(BuildContext context) {
    final eventNotifier = EventInherited.of(context).eventNotifier;
    ...

>Solution :

You can use the late modifier.

class _EventListState extends State<EventList> {
  late final eventNotifier = EventInherited.of(context).eventNotifier;
  @override
  Widget build(BuildContext context) {
    ...