protected void consolidateElementsIfLoaded() {
   if (elementsToAdd.get().size() + elementsToRemove.get().size() > 0) {
     VBox<FunctionalSet<E2>> box = getElementsBox();
     if (box.hasValue()) {
       consolidateElements();
     } else {
       // here we write the NOT_LOADED_VALUE to force the box to go to the write-set
       box.putNotLoadedValue();
     }
   }
 }
 private FunctionalSet<E2> elementSet() {
   consolidateElements();
   return getElementsBox().get(listHolder, attributeName);
 }