RehydrationToken
public struct RehydrationToken : IJsonModel<RehydrationToken>, IPersistableModel<RehydrationToken>, IJsonModel<object>, IPersistableModel<object>
Represents a token that can be used to rehydrate a long-running operation.
Gets an ID representing the operation that can be used to poll for
the status of the long-running operation.
There are cases that operation id is not available, we return "NOT_SET" for unavailable operation id.