/** * Constructs a new instance. * * @param string $source_currency_code * The code of the source currency. * @param string $destination_currency_code * The code of the destination currency. * @param string $rate * The exchange rate. * @param string $exchange_rate_provider_id * The ID of the exchange rate provider that provided this rate. */ public function __construct($source_currency_code, $destination_currency_code, $rate, $exchange_rate_provider_id) { parent::__construct($source_currency_code, $destination_currency_code, $rate); $this->exchangeRateProviderId = $exchange_rate_provider_id; }