Refactor talks to keep existing tests passing

References #78

web/modules/custom/custom/src/Entity/Node/Talk.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Drupal\custom\Entity\Node;
+
+use Drupal\discoverable_entity_bundle_classes\ContentEntityBundleInterface;
+use Drupal\node\Entity\Node;
+use Drupal\paragraphs\ParagraphInterface;
+use Illuminate\Support\Collection;
+
+/**
+ * Defines an talk node class.
+ *
+ * @ContentEntityBundleClass(
+ *   label = @Translation("Talk"),
+ *   entity_type = "node",
+ *   bundle = "talk"
+ * );
+ */
+class Talk extends Node implements ContentEntityBundleInterface {
+
+  /**
+   * Find the date for the latest event.
+   *
+   * @return string|null
+   */
+  public function findLatestEventDate(): ?string {
+    return Collection::make($this->get('field_events')->referencedEntities())
+      ->map(fn(ParagraphInterface $event) => $event->get('field_date')
+        ->getString())
+      ->max();
+  }
+
+}