public function addProductQuantityDiscount(ProductQuantityDiscount $productQuantityDiscount) { if (!$this->productQuantityDiscounts->contains($productQuantityDiscount)) { $this->productQuantityDiscounts->add($productQuantityDiscount); } }
public function removeProductQuantityDiscount(ProductQuantityDiscount $productQuantityDiscount) { return $this->productQuantityDiscounts->removeElement($productQuantityDiscount); }