Function window_record 

pub fn window_record<A: ResourceApp>(
    instance: u64,
    actions: &[<A::Resource as Resource>::Action],
) -> Result<Doc, LaunchError>

The record window instance of A kept in the test workspace while A kept one per window: stamped with that window’s default identity, initialized as A creates a record, then edited with actions. Open the app over such records with HeadlessApp::with_window_records.