anchor.diff:  }
   
   class MayRebuild extends Hook<MayRebuildState> {
  -  const MayRebuild(this.shouldRebuild);
  +  const MayRebuild([this.shouldRebuild]);
   
     final ShouldRebuildMock shouldRebuild;
   
  
positive.code: 
  class MayRebuildState extends HookState<MayRebuildState, MayRebuild> {
    @override
    bool shouldRebuild() => hook.shouldRebuild();
  
    @override
    MayRebuildState build(BuildContext context) => this;
  
negative.code: import 'mock.dart';
  
  void main() {
    testWidgets('shouldRebuild defaults to true', (tester) async {
      MayRebuildState first;
      var buildCount = 0;
  
      await tester.pumpWidget(
        HookBuilder(builder: (c) {
          buildCount++;
          first = Hook.use(const MayRebuild());
  
          return Container();
        }),
      );
  
      expect(buildCount, 1);
  
      first.markMayNeedRebuild();
      await tester.pump();
  
      expect(buildCount, 2);
    });
    testWidgets('can queue multiple mayRebuilds at once', (tester) async {
      final firstSpy = ShouldRebuildMock();
      final secondSpy = ShouldRebuildMock();
  