protected function getAddPageRoute(EntityTypeInterface $entity_type) {
    $route = new Route("/admin/openy/settings/mappings/{$entity_type->id()}/add");
    $route
      ->setDefaults([
        '_controller' => 'Drupal\openy_mappings\Controller\MappingAddController::add',
        '_title' => "Add {$entity_type->getLabel()}",
      ])
      ->setRequirement('_entity_create_access', $entity_type->id())
      ->setOption('_admin_route', TRUE);

    return $route;
  }