return i;
        }
      }
    }
    return -1;
  }

  /** Returns an implementation of {@link List#listIterator(int)}. */
  static <E extends @Nullable Object> ListIterator<E> listIteratorImpl(List<E> list, int index) {
    return new AbstractListWrapper<>(list).listIterator(index);
  }

  /** An implementation of {@link List#subList(int, int)}. */