public function setquantity($request)
{
$product = $this->buyableFromRequest();
$quantity = (int) $request->getVar('quantity');
if ($product) {
$this->cart->setQuantity($product, $quantity, $request->getVars());
}
$this->updateLocale($request);
$this->extend('updateSetQuantityResponse', $request, $response, $product, $quantity);
return $response ? $response : self::direct();
}