What is the analogue to CKSyncEngine for public databases

I modified this piece:

```
func initializeSyncEngine() {
var configuration = CKSyncEngine.Configuration(
database: Self.container.publicCloudDatabase, // <<<<<<<<<<<<<<<<<<<<< THIS
stateSerialization: self.appData.stateSerialization,
delegate: self
)
```
And hit the error:

```
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'CKSyncEngine cannot be used in the Public database'
*** First throw call stack:
```

So I read (quickly 😄 ) the documentation and noticed this tid-bit:

So, basically my question is , what is the alternative to `CKSyncEngine` providing the easiest way to sync a local database with the remote public iCloud?

Start at the initializeSyncEngine function and the CKSyncEngine.Configuration setup shown in the issue, then consult Apple’s CloudKit documentation for public-database support. Identify a supported approach for syncing a local database with the public database; the work is done when that approach and its limitations are documented.

Written by the indexing model from the issue text.