code: private function countryNameToISO3166($countryName)
      {
          foreach (explode(',', self::COUNTRIES) as $countryCode) {
              $generatedCountryName = \Locale::getDisplayRegion('-'.$countryCode, 'EN');
              if (0 === strcasecmp($countryName, $generatedCountryName)) {
                  return $countryCode;
                  break;
              }
          }
  
          return '';
      }
docs: @param $countryName
  
  @return string