Hello, is there any way to check an objectId doesnt exist in SpiceDb without iterating and gathering all children objects to do an exlcude ? I have a tree like teams/subteams and each have users with relation to the team they are in, users are created in a separate system first, and I would like to find if there is any new user that was not assigned to any team. So now either I loop trough all teams/subteams one by one and gather all users or I do a lookup or permission check on each of the users from external system one by one to see which are not in SpiceDb. Any better idea ?