iOS | cached contacts

How do I access cached contacts in SDK?

I have seen method startLoadingCaches() but no further explanation. Im trying to implement Siri voice calling but I need to access contacts in Rainbow when application is not connected to the network at the time when Siri request is called.

NotificationCenter.default.addObserver(self, selector: #selector(didFetchContactsFromCache(notification:)), name: NSNotification.Name(kContactsManagerServiceDidEndLoadingContactsFromCaches), object: nil)

But when Im checking servicesManager.contactsManagerService.contacts.count still return 0.