};
    }
    return wrapper.subList(fromIndex, toIndex);
  }

  private static class AbstractListWrapper<E extends @Nullable Object> extends AbstractList<E> {
    final List<E> backingList;

    AbstractListWrapper(List<E> backingList) {
      this.backingList = checkNotNull(backingList);
    }

    @Override

          };
    }
    return wrapper.subList(fromIndex, toIndex);
  }

  private static class AbstractListWrapper<E extends @Nullable Object> extends AbstractList<E> {
    final List<E> backingList;

    AbstractListWrapper(List<E> backingList) {
      this.backingList = checkNotNull(backingList);
    }

    @Override