register
Associate taskId with a factory that builds a fresh BackgroundWorker per dispatch.
Must be called before BackgroundTaskManager.start. Throws if the registry is already sealed or taskId is already claimed by another per-id registration or a BackgroundWorkerFactory.
Throws
if the registry is sealed.
if taskId is already registered.
Register a BackgroundWorkerFactory that owns the ids in BackgroundWorkerFactory.taskIds.
Must be called before BackgroundTaskManager.start. Throws if the registry is already sealed or any of the factory's ids collide with a per-id registration or another factory.
Throws
if the registry is sealed.
if any of BackgroundWorkerFactory.taskIds is already registered, or the factory declares no ids.