Stevebauman\Inventory\Traits\InventoryTransactionTrait::sold PHP Method

    public function sold($quantity = 0, $reason = '', $cost = 0)
    {
        /*
         * If a quantity is specified, we must be using a new transaction, so we'll
         * set the quantity attribute
         */
        if ($quantity) {
            return $this->soldAmount($quantity, $reason, $cost);
        }
        /*
         * Make sure the previous state of the transaction was
         * checked out, opened, reserved, returned/partially returned or back ordered
         */
        $this->validatePreviousState([$this::STATE_OPENED, $this::STATE_COMMERCE_CHECKOUT, $this::STATE_COMMERCE_RESERVED, $this::STATE_COMMERCE_BACK_ORDERED, $this::STATE_COMMERCE_RETURNED, $this::STATE_COMMERCE_RETURNED_PARTIAL], $this::STATE_COMMERCE_SOLD);
        /*
         * Mark the current state sold
         */
        $this->setAttribute('state', $this::STATE_COMMERCE_SOLD);
        return $this->processSave('inventory.transaction.sold');
    }