Interface Task

Attempts to cancel the task. The task may still succeed if it is unable to be canceled. If the task is canceled, then its run function will reject the promise. If cancel is called before run, then run must immediately reject the returned promise. If cancel is called after run, then nothing happens.

Describes the task for the purpose of logging.

Runs the unit of work until it either succeeds and fulfills the promise or fails and rejects the promise. Where possible it should listen for the cancellation signal, stop working, and reject the promise. If run is called more than once, it should immediately reject the promise.

Sets the parent of this task for the purpose of logging.