Learning Flutter for the first time. return ListView widget

I’m playing arround with Flutter and the first app demo from their codelab. I don’t understand why this doesn’t work:

class HistoryList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    var appState = context.watch<MyAppState>();

    if (appState.history.isEmpty) {
      return Center(
        child: Text('No history yet.'),
      );
    } else {
      return ListView(
        children: [
          for (var hist in appState.history)
            ListTile(
              leading: Icon(Icons.favorite),
              title: Text(hist.asLowerCase),
            ),
        ],
      );
    }
  }
}

but this works:

class HistoryList extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    var appState = context.watch<MyAppState>();

    if (appState.history.isEmpty) {
      return Center(
        child: Text('No history yet.'),
      );
    } else {
      return Text(appState.history.firstOrNull.toString());
    }
  }
}

I’m not getting anything in VSCode debug console but the app just crashes when I try to return a ListView instead of a Text.

Thanks for any help