code: @Override
    public int compareTo(Cut<C> that) {
      if (that == belowAll()) {
        return 1;
      }
      if (that == aboveAll()) {
        return -1;
      }
      int result = Range.compareOrThrow(endpoint, that.endpoint);
      if (result != 0) {
        return result;
      }
      // same value. below comes before above
      return Booleans.compare(this instanceof AboveValue, that instanceof AboveValue);
    }
docs: note: overridden by {BELOW,ABOVE}_ALL