retrieve
Retrieves a Flow of List<CartographicBoundary>.
This method retrieves CartographicBoundary data along with any existing associated Region entities. It utilizes Flow to emit data asynchronously.
To avoid emitting duplicate CartographicBoundary entries, it maintains a set of IDs (cartographicBoundariesSet). Only new (unseen) entries are emitted.
Retrieves a Flow of CartographicBoundary objects that contain a specific Region.
This method utilizes a Flow to potentially emit updates in the future if a CartographicBoundary containing the provided region is inserted, updated, or deleted in the database. The initial emission will be null if no matching CartographicBoundary is found for the provided region.
Return
a Flow of CartographicBoundary objects (can be null initially) that might emit updates in the future based on changes in the database.
Parameters
the region used to search for containing CartographicBoundaries.