public function has($sourceName, $currencyCode, \DateTime $date = null, $rateType = RateType::MEDIAN)
    {
        if ($date === null) {
            $date = new \DateTime('now');
        }

        try {
            return (bool)$this->get($sourceName, $currencyCode, $date, $rateType);
        } catch (ExchangeRateException $e) {
            return false;
        }
    }
public function has($sourceName, $currencyCode, \DateTime $date = null, $rateType = RateType::MEDIAN)
    {
        if ($date === null) {
            $date = new \DateTime('now');
        }

        try {
            return (bool)$this->get($sourceName, $currencyCode, $date, $rateType);
        } catch (ExchangeRateException $e) {
            return false;
        }
    }
{@inheritdoc}