How to use find.byType matching of List in Flutter widget testing

I want to do widget testing for a Stack. Here is the sample code

final List<Widget> children = [];
final stack = Stack(children: children);
await tester.pumpWidget(Container(child: stack));
...

final stackFinder = find.byWidget(stack);
expect(stackFinder, findsOneWidget);

// children should be in Stack
final childrenFinder = find.descendant(
  of: stackFinder,
  matching: find.byType(children.runtimeType),
);
expect(childrenFinder, findsWidgets);

but get error:

Expected: at least one matching node in the widget tree
  Actual: ?:<zero widgets with type "List<Widget>" that has ancestor(s) with type "Stack"

I try to change matching to matching: find.byType([].runtimeType), or matching: find.byType(List<Widget>), but it doesn't work too.

Do you know how to fix it?