token expected to be passed to resume()
Exception instance to be thrown by the next start()/resume() call.
the message passed to the resume() call which made this call resume. Its active member may be exc; for compatibility reasons this method does not throw in this case in contrast to resume().
KilledException if the fiber is killed.
In: e must not be null and the fiber must be running (not waiting or finished).
Suspends the fiber coroutine, makes the resuming start()/resume() call throw e and waits until the fiber is resumed or killed.