Joachim Noreiko
--- a/src/ToolbarHandler.php
+++ b/src/ToolbarHandler.php
   *   The cache tags.
   */
  public function getCacheTags(): array {
-    /* @var EnvironmentIndicator[] $environment_entities */
-    if (!$environment_entities = EnvironmentIndicator::loadMultiple()) {
-      return [];
-    }
-
-    $cache_tags = [];
-    foreach ($environment_entities as $entity) {
-      $cache_tags = Cache::mergeTags($cache_tags, $entity->getCacheTags());
-    }
-
-    return $cache_tags;
+    return \Drupal::entityTypeManager()->getDefinition('environment_indicator')->getListCacheTags();
-    return \Drupal::entityTypeManager()->getDefinition('environment_indicator')->getListCacheTags();
+    return $this->entityTypeManager->getDefinition('environment_indicator')->getListCacheTags();