code: func (e extensionEntry) EventUpdate(oldObject api.StoreObject) api.Event {
  	if oldObject != nil {
  		return api.EventUpdateExtension{Extension: e.Extension, OldExtension: oldObject.(extensionEntry).Extension}
  	}
  	return api.EventUpdateExtension{Extension: e.Extension}
  }
docs: // ensure that when update events are emitted, we unwrap extensionEntry