protected function addDates(array $dates = [])
    {
        foreach (['OutboundDates', 'InboundDates'] as $date) {
            if (!empty($this->data->Dates->$date)) {
                foreach ($this->data->Dates->$date as $key => $datum) {
                    $dates[$key] = $this->syncQuotes($datum, [], 'QuoteIds');
                }
            }
        }
        return $dates;
    }