Adopting SwiftData for a Core Data app - Error?

Hello everyone!

I'm trying to run this project by Apple, but it doesn't let me, I'm trying to learn more about to swiftData...

https://developer.apple.com/documentation/coredata/adopting_swiftdata_for_a_core_data_app

On the code it says next:

`@MainActor #Preview { AddBucketListItemView(trip: .preview) .modelContainer(PreviewSampleData.container) }

But it show me next error,

Type 'Trip' has no member 'preview'

anybody knows how can I solved, thank you.