return new RealizedElementCollectionIterator(getInserted(), NO_DUPLICATES);
    }

    @Override
    public Iterator<T> iteratorNoFlush() {
        return new RealizedElementCollectionIterator(getInserted(), NO_DUPLICATES);
    }

    @Override
    public boolean add(T element) {
        modCount++;
        if (nonProvidedValues.add(element)) {
            getInserted().add(new Element<T>(element));
            return true;

    }

    @Override
    public Iterator<T> iteratorNoFlush() {
        return listIterator();
    }

    @Override
    public ListIterator<T> listIterator() {
        return new RealizedElementListIterator(getInserted(), ALWAYS_ACCEPT);
    }

    @Override
    public ListIterator<T> listIterator(int index) {
        return Lists.newArrayList(listIterator()).listIterator(index);
    }

    @Override

    private Action<T> pendingAddedAction;
    private EventSubscriptionVerifier<T> subscriptionVerifier = type -> false;

    protected int modCount;

    List<Element<T>> getInserted() {
        return inserted;
    }

    @Override
    public boolean isEmpty() {
        for (Element<T> element : inserted) {
            if (element.size() != 0) {
                return false;