What are some examples of using NSFileProviderExtension in Swift?

From the docs:

https://developer.apple.com/documentation/fileprovider

If your application primarily focuses on storing and managing user documents, you can implement a file provider extension to give users access to their content while they are using other applications. A file provider provides access to files stored on your server. File provider extension:

• Creates placeholders for deleted files that you download only as needed.
• Intercepts coordinated reads from the main application so that the file can be downloaded or updated from a remote server prior to reading.
• Triggers a notification after matching entries from the main application so that the extension can upload changes to the remote server as needed.
• Lists stored documents and folders.
• Performs actions such as importing, moving, renaming, or deleting items - on saved documents and folders.