* @throws IllegalArgumentException if {@code limitSize} is negative
   * @since 3.0
   */
  public static <T extends @Nullable Object> Iterator<T> limit(
      Iterator<T> iterator, int limitSize) {
    checkNotNull(iterator);
    checkArgument(limitSize >= 0, "limit is negative");
    return new Iterator<T>() {
      private int count;

      @Override