Closes a SPARQL connection asynchronously.
No other API calls than unref should happen after this call.
| this |
A `TrackerSparqlConnection` |
| cancellable |
Optional [type@Gio.Cancellable] |
| callback |
User-defined [type@Gio.AsyncReadyCallback] to be called when the asynchronous operation is finished. |
| user_data |
User-defined data to be passed to |