public function update($sku, Closure $action)
    {
        $product = $this->pick($sku);

        $product->action($action);
    }
public function update($sku, Closure $action)
    {
        $product = $this->pick($sku);

        $product->action($action);
    }
public function update ( $ sku , Closure $ action ) { $ product = $ this -> pick ( $ sku ) ; $ product -> action ( $ action ) ; }
Update a product that is already in the basket

@param string $sku
@param Closure $action
@return void
Update a product that is already in the basket