popRoute abstract method

Called by the Router when the Router.backButtonDispatcher reports that the operating system is requesting that the current route be popped.

The method should return a boolean Future to indicate whether this delegate handles the request. Returning true indicates that the request has been handled and prevents it from bubbling up. Returning false means this delegate did not handle the request, so the request may continue to a parent BackButtonDispatcher in a nested Router setup. If the request reaches the root WidgetsBinding and remains unhandled, the platform is requested to pop the application by calling SystemNavigator.pop.

Consider using a SynchronousFuture if the result can be computed synchronously, so that the Router does not need to wait for the next microtask to schedule a build.