public static interface
Like an ExecutorService, but simpler.
It is not up to the client to decide whether to terminate the backing Executor or not.
They simply get to say that they are done with it
boolean stop(long timeout,
The executor will accept no more tasks.
It will complete executing all currently enqueued tasks, if possible.
This method will return when all tasks have run or when the timeout elapses, whichever comes first.
timeout - time to wait for shutdown
unit - time unit for shutdown wait
Returns: true if all scheduled tasks have been completed