dispose method Null safety
Tear down and clean up all resources associated with this CallClient.
Any controllers attached to streams of this CallClient have to be individually disposed, ideally before this method is called.
Implementation
Future<void> dispose() async {
await _clientEventSubscription.cancel();
await _platformEventSubscription.cancel();
await _eventsController.close();
_platformBridge.destroyCallClient(_native);
}