docs: public static @NotNull String validFilename(@NotNull String value) {
      String fileExtension = StringUtils.substringAfterLast(value, ".");
      String fileName = StringUtils.substringBeforeLast(value, ".");
      if (StringUtils.isEmpty(fileExtension)) {
        return validName(fileName);
      }
      return validName(fileName) + "." + validName(fileExtension);
    }