Retrieves the restore token of this.
A restore token will only be available if `XDP_PERSIST_MODE_TRANSIENT` or `XDP_PERSIST_MODE_PERSISTENT` was passed when creating the screencast session.
Remote desktop sessions cannot be restored.
May only be called after this is successfully started, i.e. after [[email protected]_finish].
this |
a [class@Session] |
the restore token of this |