src/main/java/io/reactivex/Single.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.COMPUTATION)
    public final Single<T> delay(long time, TimeUnit unit) {
        return delay(time, unit, Schedulers.computation(), false);
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.COMPUTATION)
    public final Single<T> delay(long time, TimeUnit unit) {
        return delay(time, unit, Schedulers.computation(), false);
    }
Delays the emission of the success signal from the current Single by the specified amount.
An error signal will not be delayed.
<p>
<img width="640" height="457" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Single.delay.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code delay} operates by default on the {@code computation} {@link Scheduler}.</dd>
</dl>

@param time the amount of time the success signal should be delayed for
@param unit the time unit
@return the new Single instance
@since 2.0