Постоянная popStateEvent
Реализация
static const EventStreamProvider<PopStateEvent> popStateEvent =
const EventStreamProvider<PopStateEvent>('popstate');
© 2012 the Dart project authors
Licensed under the BSD 3-Clause "New" or "Revised" License.
https://api.dart.dev/stable/2.18.5/dart-html/WindowEventHandlers/popStateEvent-constant.html
