// To avoid a self retain cycle under j2objc, we store Optional.absent() instead of
  // Optional.of(this). To access the delegate iterable, call #getDelegate(), which converts to
  // absent() back to 'this'.
  private final Optional<Iterable<E>> iterableDelegate;

  /** Constructor for use by subclasses. */
  protected FluentIterable() {
    this.iterableDelegate = Optional.absent();
  }

  // To avoid a self retain cycle under j2objc, we store Optional.absent() instead of
  // Optional.of(this). To access the delegate iterable, call #getDelegate(), which converts to
  // absent() back to 'this'.
  private final Optional<Iterable<E>> iterableDelegate;

  /** Constructor for use by subclasses. */
  protected FluentIterable() {
    this.iterableDelegate = Optional.absent();
  }