code: def country_code(self, fmt: Optional[CountryCode] = CountryCode.A2) -> str:
          
          key = self._validate_enum(fmt, CountryCode)
          return self.random.choice(COUNTRY_CODES[key])
docs: Get a random code of country.
  
          Default format is :attr:`~enums.CountryCode.A2` (ISO 3166-1-alpha2),
          you can change it by passing parameter ``fmt`` with enum object
          :class:`~enums.CountryCode`.
  
          :param fmt: Enum object CountryCode.
          :return: Country code in selected format.
          :raises KeyError: if fmt is not supported.