of static method
Returns the OverlayState from the closest Overlay ancestor.
Throws a StateError if no Overlay ancestor is found.
Implementation
static OverlayState of(BuildContext context) {
final state = maybeOf(context);
if (state == null) {
throw StateError(
'Overlay.of() called with a context that does not contain an Overlay.',
);
}
return state;
}