code: protected function resolveTaxRule(CountryInterface $country, $business = false): ?TaxRuleInterface
      {
          if ($business) {
              return $this->taxRuleRepository->findOneByCountryForBusiness($country);
          }
  
          return $this->taxRuleRepository->findOneByCountryForCustomer($country);
      }
docs: Resolves the tax rule for the given sale.
  
  @param CountryInterface $country
  @param bool             $business
  
  @return TaxRuleInterface|null