Issue #2707689: NodeForm::actions() checks for delete access on new entities

core/lib/Drupal/Core/Entity/Exception/MissingBundleClassException.php

+<?php
+
+namespace Drupal\Core\Entity\Exception;
+
+/**
+ * Exception thrown if a bundle class does not exist.
+ *
+ * @see \Drupal\Core\Entity\ContentEntityStorageBase::getEntityClass()
+ */
+class MissingBundleClassException extends \Exception {
+
+  /**
+   * Constructs a MissingBundleClassException.
+   *
+   * @param string $bundle_class
+   *   The bundle class which should exist.
+   */
+  public function __construct(string $bundle_class) {
+    $message = sprintf('Bundle class %s does not exist.', $bundle_class);
+    parent::__construct($message);
+  }
+
+}