code: public static function countryCodeTwoToThree($code)
      {
          $codes = array_flip(self::$_countryCodes);
          if (!array_key_exists($code, $codes)) {
              return false;
          }
  
          return $codes[$code];
      }
docs: Converts two digit country code to three digit one or return false if code does not exists
  
  @param string $code Two digit country code
  @return string|false