How to get originalObject in Live Query update event

I am trying to get the original Object in Parse JS Client SDK on update, which only relays the updated message and not the original. The architecture on Parse Server documentation says that The Publisher sends both original object and the updated object to The Subscriber which then relays to the client, but on the client I can’t get the original object. Is there something I am missing.

If this is not possible though the update API, is there any other way to achieve this functionality, other than to manually store the older object.

Refer: JavaScript Developers Guide update-event | Parse (parseplatform.org)

subscription.on('update', (object, original) => {
  console.log('object updated');
});

Thanks for the info, found the Subscription API documentation. This should probably be stated in the Guide.