}

  @GwtIncompatible // super.subListUnchecked does not exist; inherited subList is valid if slow
  /*
   * TODO(cpovirk): if we start to override indexOf/lastIndexOf under GWT, we'll want some way to
   * override subList to return an ImmutableSortedAsList for better performance. Right now, I'm not
   * sure there's any performance hit from our failure to override subListUnchecked under GWT
   */
  @Override

    } else if (length == 0) {
      return of();
    } else {
      return subListUnchecked(fromIndex, toIndex);
    }
  }

  /**
   * Called by the default implementation of {@link #subList} when {@code toIndex - fromIndex > 1},
   * after index validation has already been performed.
   */
  ImmutableList<E> subListUnchecked(int fromIndex, int toIndex) {
    return new SubList(fromIndex, toIndex - fromIndex);
  }

    } else if (length == 1) {
      return of(get(fromIndex));
    } else {
      return subListUnchecked(fromIndex, toIndex);
    }
  }

  /**
   * Called by the default implementation of {@link #subList} when {@code toIndex - fromIndex > 1},
   * after index validation has already been performed.
   */
  ImmutableList<E> subListUnchecked(int fromIndex, int toIndex) {
    return new SubList(fromIndex, toIndex - fromIndex);
  }