*/
  public static <T extends @Nullable Object> List<List<T>> partition(List<T> list, int size) {
    checkNotNull(list);
    checkArgument(size > 0);
    return (list instanceof RandomAccess)
        ? new RandomAccessPartition<>(list, size)
        : new Partition<>(list, size);
  }

  private static class Partition<T extends @Nullable Object> extends AbstractList<List<T>> {
    final List<T> list;