public function toArray()
    {
        return [
            'o_msg'   => $this->overflowMessage,
            'min_qty' => $this->minimumQuantity,
            'min_msg' => $this->minimumMessage,
            'max_qty' => INF === $this->maximumQuantity ? 'INF' : $this->maximumQuantity,
            'max_msg' => $this->maximumMessage,
            'a_qty'   => INF === $this->availableQuantity ? 'INF' : $this->availableQuantity,
            'a_msg'   => $this->availableMessage,
            'r_qty'   => $this->resupplyQuantity,
            'r_msg'   => $this->resupplyMessage,
        ];
    }