ProductVariation::createItem PHP Method

    public function createItem($quantity = 1, $filter = array())
    {
        $orderitem = self::config()->order_item;
        $item = new $orderitem();
        $item->ProductID = $this->ProductID;
        $item->ProductVariationID = $this->ID;
        //$item->ProductVariationVersion = $this->Version;
        if ($filter) {
            //TODO: make this a bit safer, perhaps intersect with allowed fields
            $item->update($filter);
        }
        $item->Quantity = $quantity;
        return $item;
    }