Cancels the unit of work represented by this reference.
Cancels the unit of work represented by this reference.
Guaranteed idempotency - calling it multiple times should have the same side-effect as calling it only a single time. Implementations of this method should also be thread-safe.
true if cancellation happened, or false if another execution happened previously or concurrently.
true in case this cancelable hasn't been canceled.
Represents a Cancelable that can queried for the canceled status.