code: public function has($sourceName, $currencyCode, \DateTime $date = null, $rateType = RateType::MEDIAN)
      {
          return $this->repository->has($sourceName, CurrencyCodeUtil::clean($currencyCode), $date, $rateType);
      }
docs: {@inheritdoc}
  
  @throws \RunOpenCode\ExchangeRate\Exception\UnknownCurrencyCodeException