@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.CUSTOM)
    public final Completable observeOn(final Scheduler scheduler) {
        ObjectHelper.requireNonNull(scheduler, "scheduler is null");
        return RxJavaPlugins.onAssembly(new CompletableObserveOn(this, scheduler));
    }
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.CUSTOM)
    public final Completable observeOn(final Scheduler scheduler) {
        ObjectHelper.requireNonNull(scheduler, "scheduler is null");
        return RxJavaPlugins.onAssembly(new CompletableObserveOn(this, scheduler));
    }
@ CheckReturnValue @ NonNull @ SchedulerSupport ( SchedulerSupport . CUSTOM ) public final Completable observeOn ( final Scheduler scheduler ) { ObjectHelper . requireNonNull ( scheduler , "scheduler is null" ) ; return RxJavaPlugins . onAssembly ( new CompletableObserveOn ( this , scheduler ) ) ; }
Returns a Completable which emits the terminal events from the thread of the specified scheduler.
<p>
<img width="640" height="523" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Completable.observeOn.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code observeOn} operates on a {@link Scheduler} you specify.</dd>
</dl>
@param scheduler the scheduler to emit terminal events on
@return the new Completable instance
@throws NullPointerException if scheduler is null
Returns a Completable which emits the terminal events from the thread of the specified scheduler . <p > <img width = 640 height = 523 src = https : // raw . github . com / wiki / ReactiveX / RxJava / images / rx - operators / Completable . observeOn . png alt = > <dl > <dt > <b > Scheduler : < / b > < / dt > <dd > {