/**
  * Make a simple validation of a Purchasable instance.
  *
  * @param PurchasableInterface $purchasable   Purchasable
  * @param int                  $stockRequired Stock required
  * @param bool                 $useStock      Use stock
  *
  * @return bool|int Is valid or the number of elements that can be used
  */
 public function isValidUsingSimplePurchasableValidation(PurchasableInterface $purchasable, $stockRequired, $useStock)
 {
     if (!$purchasable->isEnabled() || $stockRequired <= 0 || $useStock && $purchasable->getStock() <= 0) {
         return false;
     }
     if ($purchasable->getStock() < $stockRequired) {
         return $purchasable->getStock();
     }
     return true;
 }