}
            }
            return true;
        } else {
            return false;
        }
    }

    @Override
    public boolean constantTimeIsEmpty() {
        return collection.constantTimeIsEmpty();
    }

    @Override
    public boolean isEmpty() {
        if (collection.isEmpty()) {
            return true;
        } else {
            for (T o : this) {

     */
    Iterator<T> iteratorNoFlush();

    /**
     * Returns false if this source is not empty or it is not fast to determine this.
     */
    boolean constantTimeIsEmpty();

    @Override
    int estimatedSize();

    boolean contains(Object element);

    boolean containsAll(Collection<?> elements);

    @Override
    boolean isEmpty();

        this.values = new TreeSet<T>(comparator);
    }

    @Override
    public boolean isEmpty() {
        return values.isEmpty() && pending.isEmpty();
    }

    @Override
    public boolean constantTimeIsEmpty() {
        return values.isEmpty() && pending.isEmpty();
    }

    @Override
    public int size() {
        int pendingSize = 0;
        for (Collectors.TypedCollector<T> collector : pending) {