public int size() {
    Set<E> delegate = delegateOrNull();
    return (delegate != null) ? delegate.size() : size;
  }

  @Override
  public boolean isEmpty() {
    return size() == 0;
  }

  @Override
  public @Nullable Object[] toArray() {
    if (needsAllocArrays()) {
      return new Object[0];
    }
    Set<E> delegate = delegateOrNull();

    }
    Set<E> delegate = delegateOrNull();
    return (delegate != null)
        ? delegate.spliterator()
        : Spliterators.spliterator(
            requireElements(), 0, size, Spliterator.DISTINCT | Spliterator.ORDERED);
  }

  @Override
  public void forEach(Consumer<? super E> action) {
    checkNotNull(action);
    Set<E> delegate = delegateOrNull();
    if (delegate != null) {