diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index cab9f5e..ad8944e 100755
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -12,9 +12,7 @@ If you have a good idea for improvement feel free to create a new issue with all
 
 ### Issues
 
-Feel free to grab any open issue implement it and create a new pull request. Most issues can be found in the `Project.md` file in the `Docs` repository.
-
-The issue information can be used to provide additional information such as priority, difficulty and type. For your first issue try to find a issue marked `[d:first]` or `[d:beginner]`.
+Feel free to grab any open issue implement it and create a new pull request. Most issues can be found in the code marked with `@todo` or in the [PROJECT.md](https://github.com/Orange-Management/Docs/blob/master/Project/PROJECT.md) file.
 
 ### Code Style
 
diff --git a/Models/NullContactElement.php b/Models/NullContactElement.php
index e3bfb70..5eff073 100755
--- a/Models/NullContactElement.php
+++ b/Models/NullContactElement.php
@@ -24,4 +24,15 @@ namespace Modules\Profile\Models;
  */
 final class NullContactElement extends ContactElement
 {
+    /**
+     * Constructor
+     *
+     * @param int $id Model id
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $id = 0)
+    {
+        $this->id = $id;
+    }
 }
diff --git a/Models/Profile.php b/Models/Profile.php
index b57aae5..22bab24 100755
--- a/Models/Profile.php
+++ b/Models/Profile.php
@@ -239,7 +239,7 @@ class Profile implements \JsonSerializable
     /**
      * {@inheritdoc}
      */
-    public function jsonSerialize()
+    public function toArray() : array
     {
         return [
             'id'              => $this->id,
@@ -252,4 +252,12 @@ class Profile implements \JsonSerializable
             'contactelements' => $this->contactElements,
         ];
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function jsonSerialize()
+    {
+        return $this->toArray();
+    }
 }
diff --git a/Theme/Backend/profile-single.tpl.php b/Theme/Backend/profile-single.tpl.php
index c80bdef..dc9f0f4 100755
--- a/Theme/Backend/profile-single.tpl.php
+++ b/Theme/Backend/profile-single.tpl.php
@@ -133,8 +133,8 @@ echo $this->getData('nav')->render();
                                 <?php else: foreach($contacts as $contact) : ?>
                                     <tr>
                                         <th><?= $this->getHtml('cType' . $contact->getType()); ?>
-                                        <td><?= $contact->getType() === ContactType::WEBSITE ? '<a href="' . $contact->getContent() . '">' : ''; ?>
-                                                <?= $contact->getContent(); ?>
+                                        <td><?= $contact->getType() === ContactType::WEBSITE ? '<a href="' . $contact->content . '">' : ''; ?>
+                                                <?= $contact->content; ?>
                                             <?= $contact->getType() === ContactType::WEBSITE ? '</a>' : ''; ?>
                                 <?php endforeach; endif; ?>
                                 <tr>
diff --git a/tests/Controller/ApiControllerTest.php b/tests/Controller/ApiControllerTest.php
index 4859176..c9aeeb0 100755
--- a/tests/Controller/ApiControllerTest.php
+++ b/tests/Controller/ApiControllerTest.php
@@ -25,17 +25,17 @@ use phpOMS\Account\PermissionType;
 use phpOMS\Application\ApplicationAbstract;
 use phpOMS\Dispatcher\Dispatcher;
 use phpOMS\Event\EventManager;
+use phpOMS\Localization\ISO3166TwoEnum;
 use phpOMS\Message\Http\HttpRequest;
 use phpOMS\Message\Http\HttpResponse;
 use phpOMS\Message\Http\RequestStatusCode;
+use phpOMS\Module\ModuleAbstract;
 use phpOMS\Module\ModuleManager;
 use phpOMS\Router\WebRouter;
+use phpOMS\Stdlib\Base\AddressType;
 use phpOMS\System\MimeType;
 use phpOMS\Uri\HttpUri;
 use phpOMS\Utils\TestUtils;
-use phpOMS\Module\ModuleAbstract;
-use phpOMS\Stdlib\Base\AddressType;
-use phpOMS\Localization\ISO3166TwoEnum;
 
 /**
  * @internal
@@ -240,6 +240,7 @@ final class ApiControllerTest extends \PHPUnit\Framework\TestCase
         $this->module->apiAddressCreate($request, $response);
         self::assertGreaterThan(0, $response->get('')['response']->getId());
     }
+
     /**
      * @covers Modules\Profile\Controller\ApiController
      * @group module
diff --git a/tests/Models/ContactTest.php b/tests/Models/ContactTest.php
index 54c1458..ff2334a 100644
--- a/tests/Models/ContactTest.php
+++ b/tests/Models/ContactTest.php
@@ -44,7 +44,7 @@ final class ContactTest extends \PHPUnit\Framework\TestCase
         self::assertEquals('', $this->contact->description);
         self::assertEquals('', $this->contact->company);
         self::assertEquals('', $this->contact->job);
-        self::assertEquals(null, $this->contact->birthday);
+        self::assertNull($this->contact->birthday);
         self::assertInstanceOf('\Modules\Media\Models\Media', $this->contact->image);
     }
 }
diff --git a/tests/Models/NullContactElementTest.php b/tests/Models/NullContactElementTest.php
new file mode 100644
index 0000000..7c5184d
--- /dev/null
+++ b/tests/Models/NullContactElementTest.php
@@ -0,0 +1,42 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 8.0
+ *
+ * @package   tests
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace Modules\Profile\tests\Models;
+
+use Modules\Profile\Models\NullContactElement;
+
+/**
+ * @internal
+ */
+final class NullContactElementTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\Profile\Models\NullContactElement
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\Profile\Models\ContactElement', new NullContactElement());
+    }
+
+    /**
+     * @covers Modules\Profile\Models\NullContactElement
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullContactElement(2);
+        self::assertEquals(2, $null->getId());
+    }
+}