fix: fake handle in case it does not exist

src/Entity/Domain.php

@@ -106,6 +106,9 @@ class Domain
     #[Groups(['domain:item', 'domain:list', 'watchlist:item', 'watchlist:list'])]
     private ?bool $deleted;
 
+    #[Groups(['domain:item'])]
+    private ?RdapServer $rdapServer;
+
     /**
      * @var Collection<int, DomainStatus>
      */
@@ -423,4 +426,14 @@ class Domain
 
         return $this;
     }
+
+    public function getRdapServer(): ?RdapServer
+    {
+        return $this->rdapServer;
+    }
+
+    public function setRdapServer(?RdapServer $rdapServer): void
+    {
+        $this->rdapServer = $rdapServer;
+    }
 }

src/Entity/RdapServer.php

@@ -5,12 +5,14 @@ namespace App\Entity;
 use App\Repository\RdapServerRepository;
 use Doctrine\DBAL\Types\Types;
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Serializer\Attribute\Groups;
 
 #[ORM\Entity(repositoryClass: RdapServerRepository::class)]
 class RdapServer
 {
     #[ORM\Id]
     #[ORM\Column(length: 255)]
+    #[Groups(['domain:item'])]
     private ?string $url = null;
 
     #[ORM\Column(type: Types::DATE_IMMUTABLE)]