code: void notifyParentChanged(List<ParentChangedEvent> events) {
          for (int i = 0; i < events.size(); ++i) {
              ParentChangedEvent event = events.get(i);
              stateOnlyRemovalQueue.priorityChanged(event.state);
              if (event.state.parent != null && event.state.activeCountForTree != 0) {
                  event.state.parent.offerAndInitializePseudoTime(event.state);
                  event.state.parent.activeCountChangeForTree(event.state.activeCountForTree);
              }
          }
      }
docs: Notify all listeners of the priority tree change events (in ascending order)
  @param events The events (top down order) which have changed