anchor.diff:  
     /// Resolves any closures that were deferred by [_visitArguments].
     void _resolveDeferredClosures(
  -      {required FunctionType? rawType,
  -      required Iterable<_DeferredClosure> deferredClosures,
  +      {required Iterable<_DeferredClosure> deferredClosures,
         List<EqualityInfo<PromotableElement, DartType>?>? identicalInfo,
         Substitution? substitution,
         GenericInferrer? inferrer}) {
  
positive.code:   final ResolverVisitor resolver;
    final Node node;
    final ArgumentListImpl argumentList;
    final FunctionType? rawType;
    final DartType? contextType;
    final List<WhyNotPromotedGetter> whyNotPromotedList;
  
  
negative.code:               rawType!.typeFormals, inferrer.partialInfer());
          }
          _resolveDeferredClosures(
              deferredClosures: stage,
              identicalInfo: identicalInfo,
              substitution: substitution,
  