Weight, how can deal with this? about laravelshoppingcart HOT 3 CLOSED

/**
     * get total weight of items in the cart
     *
     * @return int
     */
    public function getTotalWeight()
    {
        $items = $this->getContent();

        if( $items->isEmpty() ) return 0;

        $count = $items->sum(function($item)
        {
            return $item['weight'] * $item['quantity'];
        });

        return $count;
    }

public function add($id, $name = null, $price = null, $quantity = null, $weight = null,  $attributes = array(), $conditions = array())
    {
        // if the first argument is an array,
        // we will need to call add again
        if( is_array($id) )
        {
            // the first argument is an array, now we will need to check if it is a multi dimensional
            // array, if so, we will iterate through each item and call add again
            if( Helpers::isMultiArray($id) )
            {
                foreach($id as $item)
                {
                    $this->add(
                        $item['id'],
                        $item['name'],
                        $item['price'],
                        $item['quantity'],
                        $item['weight'],
                        Helpers::issetAndHasValueOrAssignDefault($item['attributes'], array()),
                        Helpers::issetAndHasValueOrAssignDefault($item['conditions'], array())
                    );
                }
            }
            else
            {
                $this->add(
                    $id['id'],
                    $id['name'],
                    $id['price'],
                    $id['quantity'],
                    $id['weight'],
                    Helpers::issetAndHasValueOrAssignDefault($id['attributes'], array()),
                    Helpers::issetAndHasValueOrAssignDefault($id['conditions'], array())
                );
            }

            return $this;
        }

        // validate data
        $item = $this->validate(array(
            'id' => $id,
            'name' => $name,
            'price' => Helpers::normalizePrice($price),
            'quantity' => $quantity,
            'weight' => $weight,
            'attributes' => new ItemAttributeCollection($attributes),
            'conditions' => $conditions,
        ));

        // get the cart
        $cart = $this->getContent();

        // if the item is already in the cart we will just update it
        if( $cart->has($id) )
        {
            $this->events->fire($this->getInstanceName().'.updating', array($item, $this));

            $this->update($id, $item);

            $this->events->fire($this->getInstanceName().'.updated', array($item, $this));
        }
        else
        {
            $this->events->fire($this->getInstanceName().'.adding', array($item, $this));

            $this->addRow($id, $item);

            $this->events->fire($this->getInstanceName().'.added', array($item, $this));
        }

        return $this;
    }