pageBuilder property
        
        GoRouterPageBuilder?
        pageBuilder
        
      
finalinherited
      A page builder for this route.
Typically a MaterialPage, as in:
GoRoute(
  path: '/',
  pageBuilder: (BuildContext context, GoRouterState state) => MaterialPage<void>(
    key: state.pageKey,
    child: HomePage(families: Families.data),
  ),
),
You can also use CupertinoPage, and for a custom page builder to use
custom page transitions, you can use CustomTransitionPage.
Implementation
final GoRouterPageBuilder? pageBuilder;