src/main/java/io/reactivex/Completable.java
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public static <T> Completable fromMaybe(final MaybeSource<T> maybe) {
        ObjectHelper.requireNonNull(maybe, "maybe is null");
        return RxJavaPlugins.onAssembly(new MaybeIgnoreElementCompletable<T>(maybe));
    }
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public static <T> Completable fromMaybe(final MaybeSource<T> maybe) {
        ObjectHelper.requireNonNull(maybe, "maybe is null");
        return RxJavaPlugins.onAssembly(new MaybeIgnoreElementCompletable<T>(maybe));
    }
Returns a Completable instance that when subscribed to, subscribes to the {@code Maybe} instance and
emits a completion event if the maybe emits {@code onSuccess}/{@code onComplete} or forwards any
{@code onError} events.
<p>
<img width="640" height="235" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Completable.fromMaybe.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code fromMaybe} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>
<p>History: 2.1.17 - beta
@param <T> the value type of the {@link MaybeSource} element
@param maybe the Maybe instance to subscribe to, not null
@return the new Completable instance
@throws NullPointerException if single is null
@since 2.2