public static Integer parseIntSubstring(String tag) {
    if (tag == null) {
      return null;
    }
    try {
      var matcher = INT_SUBSTRING_PATTERN.matcher(tag);
      return matcher.find() ? Integer.parseInt(matcher.group(1)) : null;
    } catch (NumberFormatException e) {
      return null;
    }
  }
Returns {@code tag} as an integer or null if invalid, ignoring any non-numeric suffix.
planetiler-core/src/main/java/com/onthegomap/planetiler/util/Parse.java