public function getCheckPayload(Customer $customer, Order $order, $previous_orders)
    {
        $payload = json_encode(array(
            'random_nonce' => uniqid('', true),
            'customer' => $customer->serialize(),
            'order' => $order->serialize(),
            'previous_orders' => array_map(function (Order $item) {
                return $item->serialize();
            }, $previous_orders)
        ));
        return $this->encrypt($this->compress($payload));
    }