T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }

  /**
   * Returns the next element in the iteration without advancing the iteration, according to the
   * contract of {@link PeekingIterator#peek()}.
   *
   * <p>Implementations of {@code AbstractIterator} that wish to expose this functionality should
   * implement {@code PeekingIterator}.
   */
  @ParametricNullness

    T result = uncheckedCastNullableTToT(next);
    next = null;
    return result;
  }

  /**
   * Returns the next element in the iteration without advancing the iteration, according to the
   * contract of {@link PeekingIterator#peek()}.
   *
   * <p>Implementations of {@code AbstractIterator} that wish to expose this functionality should
   * implement {@code PeekingIterator}.
   */
  @ParametricNullness