src/main/java/io/reactivex/Maybe.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.COMPUTATION)
    public final Maybe<T> delay(long delay, TimeUnit unit) {
        return delay(delay, unit, Schedulers.computation());
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.COMPUTATION)
    public final Maybe<T> delay(long delay, TimeUnit unit) {
        return delay(delay, unit, Schedulers.computation());
    }
Returns a Maybe that signals the events emitted by the source Maybe shifted forward in time by a
specified delay.
<p>
<img width="640" height="310" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/delay.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>This version of {@code delay} operates by default on the {@code computation} {@link Scheduler}.</dd>
</dl>

@param delay
the delay to shift the source by
@param unit
the {@link TimeUnit} in which {@code period} is defined
@return the new Maybe instance
@see <a href="http://reactivex.io/documentation/operators/delay.html">ReactiveX operators documentation: Delay</a>