docs: def normalize_locale_code(locale: Union[Locale, str]) -> str:
      """Determine the normalized locale code string.
  
      >>> normalize_locale_code('ko-kr')
      'ko_KR'
      >>> normalize_locale_code('zh_TW')
      'zh_Hant_TW'
      >>> normalize_locale_code(Locale.parse('en_US'))
      'en_US'
  
      """
      if not isinstance(locale, Locale):
          locale = Locale.parse(locale.replace('-', '_'))
      return str(locale)