/**
  * @param Product $product
  */
 private function saveRewards($product)
 {
     if ($product->isRewardsModified()) {
         $this->getDb()->query("DELETE FROM product_reward WHERE product_id = '" . (int) $product->getId() . "'");
         foreach ($product->getRewards() as $customer_group_id => $value) {
             $this->getDb()->query("INSERT INTO product_reward SET product_id = '" . (int) $product->getId() . "', customer_group_id = '" . (int) $customer_group_id . "', points = '" . (int) $value['points'] . "'");
         }
     }
 }