code: def test_send_error_on_set(
      monkeypatch: MonkeyPatch,
      notification_service: NotificationService,
      authed_context: AuthedServiceContext,
      mock_create_notification: CreateNotification,
  ) -> None:
      def mock_set(*args, **kwargs) -> Err:
          return Err(expected_error)
  
      test_notification_service = notification_service
      expected_error = "Failed to set notification."
  
      monkeypatch.setattr(notification_service.stash, "set", mock_set)
      response = test_notification_service.send(
          authed_context, mock_create_notification
      )
  
      assert isinstance(response, SyftError)
      assert response.message == expected_error
  
imports: from pytest import MonkeyPatch
  from result import Err
  from result import Ok
  from syft.node.credentials import SyftSigningKey
  from syft.node.credentials import SyftVerifyKey
  from syft.service.context import AuthedServiceContext
  from syft.service.notification.notification_service import NotificationService
  from syft.service.notification.notification_stash import NotificationStash
  from syft.service.notification.notifications import CreateNotification
  from syft.service.notification.notifications import Notification
  from syft.service.notification.notifications import NotificationStatus
  from syft.service.response import SyftError
  from syft.service.response import SyftSuccess
  from syft.store.document_store import DocumentStore
  from syft.store.linked_obj import LinkedObject
  from syft.types.datetime import DateTime
  from syft.types.uid import UID
label_desc: Use image node_id 3 for calling a global function with example usage: test_send_error_on_set(monkeypatch, notification_service, authed_context, mock_create_notification) and returns: Err