code: protected function loadDepartureDateLimits(PriceXplorerExtremeSearchOptions $params)
      {
          if ($params->earliestDepartureDate instanceof \DateTime || $params->latestDepartureDate instanceof \DateTime) {
              $this->travelDates = new TravelDates($params->earliestDepartureDate, $params->latestDepartureDate);
          }
      }
docs: @param PriceXplorerExtremeSearchOptions $params