src/main/java/io/reactivex/Maybe.java
@BackpressureSupport(BackpressureKind.FULL)
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Flowable<T> repeatWhen(final Function<? super Flowable<Object>, ? extends Publisher<?>> handler) {
        return toFlowable().repeatWhen(handler);
    }
@BackpressureSupport(BackpressureKind.FULL)
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Flowable<T> repeatWhen(final Function<? super Flowable<Object>, ? extends Publisher<?>> handler) {
        return toFlowable().repeatWhen(handler);
    }
Returns a Flowable that emits the same values as the source Publisher with the exception of an
{@code onComplete}. An {@code onComplete} notification from the source will result in the emission of
a {@code void} item to the Publisher provided as an argument to the {@code notificationHandler}
function. If that Publisher calls {@code onComplete} or {@code onError} then {@code repeatWhen} will
call {@code onComplete} or {@code onError} on the child subscription. Otherwise, this Publisher will
resubscribe to the source Publisher.
<p>
<img width="640" height="430" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/repeatWhen.f.png" alt="">
<dl>
<dt><b>Backpressure:</b></dt>
<dd>The operator honors downstream backpressure and expects the source {@code Publisher} to honor backpressure as well.
If this expectation is violated, the operator <em>may</em> throw an {@code IllegalStateException}.</dd>
<dt><b>Scheduler:</b></dt>
<dd>{@code repeatWhen} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@param handler
receives a Publisher of notifications with which a user can complete or error, aborting the repeat.
@return the source Publisher modified with repeat logic
@see <a href="http://reactivex.io/documentation/operators/repeat.html">ReactiveX operators documentation: Repeat</a>