Fixed some higher level PHPstan issues.

src/Entity/Base/TimestampTrait.php

@@ -51,14 +51,14 @@ use Symfony\Component\Serializer\Annotation\Groups;
 trait TimestampTrait
 {
     /**
-     * @var DateTime the date when this element was modified the last time
+     * @var DateTime|null the date when this element was modified the last time
      * @ORM\Column(type="datetime", name="last_modified", options={"default"="CURRENT_TIMESTAMP"})
      * @Groups({"extended", "full"})
      */
     protected $lastModified;
 
     /**
-     * @var DateTime the date when this element was created
+     * @var DateTime|null the date when this element was created
      * @ORM\Column(type="datetime", name="datetime_added", options={"default"="CURRENT_TIMESTAMP"})
      * @Groups({"extended", "full"})
      */

src/Entity/Parameters/ParametersTrait.php

@@ -39,7 +39,7 @@ trait ParametersTrait
     /**
      *  Return all associated specifications.
      *
-     * @psalm-return Collection<int, PartParameter>
+     * @psalm-return Collection<int, AbstractParameter>
      */
     public function getParameters(): Collection
     {

src/Entity/PriceInformations/Pricedetail.php

@@ -77,7 +77,7 @@ class Pricedetail extends AbstractDBElement implements TimeStampableInterface
     public const PRICE_PRECISION = 5;
 
     /**
-     * @var string The price related to the detail. (Given in the selected currency)
+     * @var BigDecimal The price related to the detail. (Given in the selected currency)
      * @ORM\Column(type="big_decimal", precision=11, scale=5)
      * @BigDecimalPositive()
      */