code: def add_mock_notification(
      root_verify_key,
      notification_stash: NotificationStash,
      from_user_verify_key: SyftVerifyKey,
      to_user_verify_key: SyftVerifyKey,
      status: NotificationStatus,
  ) -> Notification:
      # prepare: add mock
  
      mock_notification = Notification(
          subject="mock_notification",
          node_uid=UID(),
          from_user_verify_key=from_user_verify_key,
          to_user_verify_key=to_user_verify_key,
          created_at=DateTime.now(),
          status=status,
      )
  
      result = notification_stash.set(
          root_verify_key, mock_notification
      )
      assert result.is_ok()
  
      return mock_notification
  
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 1 for calling a global function with example usage: add_mock_notification(root_verify_key, notification_stash, from_user_verify_key, to_user_verify_key, status) and returns: mock_notification