src/main/java/io/reactivex/Maybe.java
@BackpressureSupport(BackpressureKind.FULL)
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Flowable<T> repeatUntil(BooleanSupplier stop) {
        return toFlowable().repeatUntil(stop);
    }
@BackpressureSupport(BackpressureKind.FULL)
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Flowable<T> repeatUntil(BooleanSupplier stop) {
        return toFlowable().repeatUntil(stop);
    }
Returns a Flowable that repeats the sequence of items emitted by the source Maybe until
the provided stop function returns true.
<p>
<img width="640" height="310" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/repeat.on.png" alt="">
<dl>
<dt><b>Backpressure:</b></dt>
<dd>This operator honors downstream backpressure.</dd>
<dt><b>Scheduler:</b></dt>
<dd>{@code repeatUntil} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@param stop
a boolean supplier that is called when the current Flowable completes and unless it returns
false, the current Flowable is resubscribed
@return the new Flowable instance
@throws NullPointerException
if {@code stop} is null
@see <a href="http://reactivex.io/documentation/operators/repeat.html">ReactiveX operators documentation: Repeat</a>