code: func (gb *GraphBuilder) enqueueVirtualDeleteEvent(ref objectReference) {
  	gb.graphChanges.Add(&event{
  		eventType: deleteEvent,
  		obj: &metaonly.MetadataOnlyObject{
  			TypeMeta:   metav1.TypeMeta{APIVersion: ref.APIVersion, Kind: ref.Kind},
  			ObjectMeta: metav1.ObjectMeta{Namespace: ref.Namespace, UID: ref.UID, Name: ref.Name},
  		},
  	})
  }
docs: // enqueueVirtualDeleteEvent is used to add a virtual delete event to be processed for virtual nodes
  // once it is determined they do not have backing objects in storage