Hi Team,

I was testing and created a Picking for Goods Return, however, when I did that, following error was created:
![image](https://user-images.githubusercontent.com/5710396/32747248-2f22e1f0-c8de-11e7-817a-17e238e928b3.png)

I checked and found that in the code instead of account.move, stock.move object was referenced.
![image](https://user-images.githubusercontent.com/5710396/32747171-e9a88832-c8dd-11e7-8c35-cd184c92cbfe.png)

Please advice.

Regards


self.product_price_update_before_done()
        res = super(StockMove, self).action_done()
        self.product_price_update_after_done()
        return res
    @api.multi
    def product_price_update_before_done(self):
        tmpl_dict = defaultdict(lambda: 0.0)
        
        std_price_update = {}
        for move in self.filtered(lambda move: move.location_id.usage in ('supplier', 'production') and move.product_id.cost_method == 'average'):
            product_tot_qty_available = move.product_id.qty_available + tmpl_dict[move.product_id.id]
            
            if product_tot_qty_available <= 0:
                new_std_price = move.get_price_unit()
            else:
                
                amount_unit = std_price_update.get((move.company_id.id, move.product_id.id)) or move.product_id.standard_price
                new_std_price = ((amount_unit * product_tot_qty_available) + (move.get_price_unit() * move.product_qty)) / (product_tot_qty_available + move.product_qty)
            tmpl_dict[move.product_id.id] += move.product_qty