Thrown when a Cosmos update loses an optimistic-concurrency race.
An update whose payload exceeds the per-request patch limit is served by a
read-merge-replace, and that replace is conditional on the _etag the read
returned. A concurrent writer between the two answers 412, which is
surfaced here rather than silently overwriting the other writer's row.
readonly
name: string
Discriminant for consumers that cannot use instanceof across realms.