more tests and make classes final

Models/DrawImage.php

@@ -33,7 +33,7 @@ class DrawImage implements \JsonSerializable, ArrayableInterface
      * @var int
      * @since 1.0.0
      */
-    private int $id = 0;
+    protected int $id = 0;
 
     /**
      * Media object.

Models/NullDrawImage.php

@@ -24,4 +24,15 @@ namespace Modules\Draw\Models;
  */
 final class NullDrawImage extends DrawImage
 {
+	/**
+     * Constructor
+     *
+     * @param int $id Model id
+     *
+     * @since 1.0.0
+     */
+    public function __construct(int $id = 0)
+    {
+        $this->id = $id;
+    }
 }

tests/Models/NullDrawImageTest.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\Draw\tests\Models;
+
+use Modules\Draw\Models\NullDrawImage;
+
+/**
+ * @internal
+ */
+final class NullDrawImageTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @covers Modules\Draw\Models\NullDrawImage
+     * @group framework
+     */
+    public function testNull() : void
+    {
+        self::assertInstanceOf('\Modules\Draw\Models\DrawImage', new NullDrawImage());
+    }
+
+    /**
+     * @covers Modules\Draw\Models\NullDrawImage
+     * @group framework
+     */
+    public function testId() : void
+    {
+        $null = new NullDrawImage(2);
+        self::assertEquals(2, $null->getId());
+    }
+}