panic(fmt.Sprintf("cannot merge into invalid %v message", dst.Descriptor().FullName()))
	}

	src.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
		switch {
		case fd.IsList():
			o.mergeList(dst.Mutable(fd).List(), v.List(), fd)
		case fd.IsMap():
			o.mergeMap(dst.Mutable(fd).Map(), v.Map(), fd.MapValue())
		case fd.Message() != nil:
			mergeFn, exists := o.customMergeFn[fd.Message().FullName()]

	specList := make([]cached.Value[*spec.Swagger], 0, len(c.specsByName))
	for crd := range c.specsByName {
		specList = append(specList, c.specsByName[crd].mergedVersionSpec)
	}

	cache := cached.MergeList(func(results []cached.Result[*spec.Swagger]) (*spec.Swagger, string, error) {
		localCRDSpec := make([]*spec.Swagger, 0, len(results))
		for k := range results {
			if results[k].Err == nil {