unsubscribe
Stops delivering a topic's messages to listener. A listener that is not subscribed to the topic is ignored.
Removing a topic's last listener suspends until the server has dropped the subscription.
Throws
3035 (also reported on onError) / 3065 when the room is not joined or is reconnecting, and 4089 (PUBSUB_UNSUBSCRIBE_FAILED, also reported on onError) when the server call fails. The listener stays registered after any of them.