String ancestorName = DOT_JOINER.join(parts.subList(i, partsSize));

      if (i > 0
          && matchesType(
              desiredType, Optional.fromNullable(PublicSuffixPatterns.UNDER.get(ancestorName)))) {
        return i - 1;
      }

      if (matchesType(
          desiredType, Optional.fromNullable(PublicSuffixPatterns.EXACT.get(ancestorName)))) {
        return i;
      }