public function process($baseCurrencyCode, RatesConfigurationRegistryInterface $configurations, array $rates)
    {
        $registry = array();

        /**
         * @var RateInterface $rate
         */
        foreach ($rates as $rate) {

            $key = sprintf('%s_%s_%s_%s', $rate->getCurrencyCode(), $rate->getRateType(), $rate->getSourceName(), $rate->getDate()->format('Y-m-d'));

            if (array_key_exists($key, $registry)) {
                throw new ConfigurationException(sprintf('Currency code "%s" of rate type "%s" from source "%s" valid on date "%s" is duplicated.', $rate->getCurrencyCode(), $rate->getRateType(), $rate->getSourceName(), $rate->getDate()->format('Y-m-d')));
            }

            $registry[$key] = $rate->getSourceName();
        }

        return $rates;
    }
public function process($baseCurrencyCode, RatesConfigurationRegistryInterface $configurations, array $rates)
    {
        $registry = array();

        /**
         * @var RateInterface $rate
         */
        foreach ($rates as $rate) {

            $key = sprintf('%s_%s_%s_%s', $rate->getCurrencyCode(), $rate->getRateType(), $rate->getSourceName(), $rate->getDate()->format('Y-m-d'));

            if (array_key_exists($key, $registry)) {
                throw new ConfigurationException(sprintf('Currency code "%s" of rate type "%s" from source "%s" valid on date "%s" is duplicated.', $rate->getCurrencyCode(), $rate->getRateType(), $rate->getSourceName(), $rate->getDate()->format('Y-m-d')));
            }

            $registry[$key] = $rate->getSourceName();
        }

        return $rates;
    }
{@inheritdoc}

@throws ConfigurationException