refactor: match new PriceFactorInterface

composer.json

@@ -21,7 +21,7 @@
     "php": ">=5.3",
     "quiqqer\/quiqqer": "*@dev",
     "quiqqer\/areas": "*@dev",
-    "quiqqer\/products": "*@dev",
+    "quiqqer\/products": "^1.6|*@dev",
     "quiqqer\/tax": "*@dev"
   },
   "autoload": {

src/QUI/ERP/Discount/PriceFactor.php

@@ -19,7 +19,7 @@ class PriceFactor extends QUI\ERP\Products\Utils\PriceFactor implements QUI\ERP\
     /**
      * @var string
      */
-    protected $type = Handler::DISCOUNT_PRICEFACTOR_TYPE;
+    protected string $type = Handler::DISCOUNT_PRICEFACTOR_TYPE;
 
     /**
      * @var string|null
@@ -70,7 +70,7 @@ public function getVatType()
     /**
      * @return array
      */
-    public function toArray()
+    public function toArray(): array
     {
         $attributes = parent::toArray();