code: public function match(AddressInterface $address)
      {
          $euCountries = [
              'AT', 'BE', 'BG', 'CY', 'CZ', 'DE', 'DK', 'EE', 'ES', 'FI',
              'FR', 'GB', 'GR', 'HR', 'HU', 'IE', 'IT', 'LT', 'LU', 'LV',
              'MT', 'NL', 'PL', 'PT', 'RO', 'SE', 'SI', 'SK',
          ];
          $countryCode = $address->getCountryCode();
  
          return in_array($countryCode, $euCountries);
      }
docs: {@inheritdoc}