public function setMaxDate($maxDate)
    {
        $date = \DateTime::createFromFormat(self::MAX_DATE_FORMAT, $maxDate);
        $isValid = $date && $date->format(self::MAX_DATE_FORMAT) == $maxDate;

        if (!$isValid) {
            throw new \InvalidArgumentException('Maximum payment date must be in that format: '.self::MAX_DATE_FORMAT);
        }

        $this->maxDate = $maxDate;
    }