workmanager library

Classes

Constraints
A specification of the requirements that need to be met before a WorkRequest can run. By default, WorkRequests do not have any requirements and can run immediately. By adding requirements, you can make sure that work only runs in certain situations - for example, when you have an unmetered network and are charging.
Workmanager
Make sure you followed the platform setup steps first before trying to register any task. Android:

Enums

BackoffPolicy
An enumeration of backoff policies when retrying work. These policies are used when you have a return ListenableWorker.Result.retry() from a worker to determine the correct backoff time. Backoff policies are set in WorkRequest.Builder.setBackoffCriteria(BackoffPolicy, long, TimeUnit) or one of its variants.
ExistingWorkPolicy
An enumeration of the conflict resolution policies in case of a collision.
NetworkType
An enumeration of various network types that can be used as Constraints for work.
OutOfQuotaPolicy
An enumeration of policies that help determine out of quota behavior for expedited jobs.