Indicates that the websocket will shut down in the near future. Until it is, SubscriptionUpdates will
still be sent to the client. Clients that want to avoid downtime or latency spikes should initiate a new
websocket and recreate all their subscriptions there but still keep this websocket open until the new
websockets starts sending SubscriptionUpdates.
Note: The initial updates that the new websocket sends might be somewhat stale because of server and
connection pools warm up. The client might want to wait with fully switching to the new subscription until
the updates aren’t very stale anymore.