OWNER

The id is its owner's: each owner has one such aggregate in its tenant, such as a buyer's basket. An owner-level caller addresses it as "mine", by no id, and admission takes the caller's owner for it; naming another id is forbidden. A caller with no owner (a tenant-level caller, a service, a saga's command) names the id. No id is ever generated, the aggregate records its id as its owner, and its owner cannot be transferred. It belongs to its owner (Ownership.OWNER).