Should `long delayTime, TimeUnit unit` become a `TimeSpan` class that holds them together like Rx.Net does or leave it the "Java way" as `ScheduledExecutorService` does (http://docs.oracle.com/javase/6/docs/api/index.html?java/util/concurrent/ScheduledExecutorService.html) with the two kept separate?

The `TimeSpan` class is a system class in .Net (http://msdn.microsoft.com/en-us/library/system.timespan(v=vs.103).aspx) whereas Java doesn't have anything like that - it's always just a `long` + `TimeUnit`

If we were to add this class should it be in `rx.concurrency` or `rx.util`? I lean towards `rx.util`.

This discussion originates from https://github.com/Netflix/RxJava/pull/228#issuecomment-16489026