Add a Presentation bundle class

Drupal core issue: https://www.drupal.org/node/2570593
Change record: https://www.drupal.org/node/3191609

modules/opd_presentations/tests/src/DrupalTestTraits/Entity/PresentationTest.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\opd_presentations\DrupalTestTraits\Entity;
+
+use Drupal\paragraphs\Entity\Paragraph;
+use Drupal\opd_presentations\Entity\Presentation;
+use weitzman\DrupalTestTraits\ExistingSiteBase;
+
+final class PresentationTest extends ExistingSiteBase {
+
+  public function test_getting_past_events(): void {
+    $presentation = $this->createPresentation(
+      events: [
+        Paragraph::create(['type' => 'event']),
+      ],
+    );
+
+    $this->assertCount(
+      expectedCount: 1,
+      haystack: $presentation->getPastEvents(),
+    );
+  }
+
+  /**
+   * @param ParagraphInterface[] $events
+   */
+  private function createPresentation(array $events): Presentation {
+    return $this->createNode([
+      'field_events' => $events,
+      'type' => 'presentation',
+    ]);
+  }
+}