RoutePresentationCallback typedef Null safety
A callback that given some arguments and a navigator adds a new
restorable route to that navigator and returns the opaque ID of that
new route.
Usually, this callback calls one of the imperative methods on the Navigator that have "restorable" in the name and returns their return value.
Used by RestorableRouteFuture.onPresent.
Implementation
typedef RoutePresentationCallback = String Function(NavigatorState navigator, Object? arguments);