src/main/java/io/reactivex/Maybe.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Maybe<T> retry(BiPredicate<? super Integer, ? super Throwable> predicate) {
        return toFlowable().retry(predicate).singleElement();
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Maybe<T> retry(BiPredicate<? super Integer, ? super Throwable> predicate) {
        return toFlowable().retry(predicate).singleElement();
    }
Returns a Maybe that mirrors the source Maybe, resubscribing to it if it calls {@code onError}
and the predicate returns true for that specific exception and retry count.
<p>
<img width="640" height="315" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/retry.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code retry} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@param predicate
the predicate that determines if a resubscription may happen in case of a specific exception
and retry count
@return the new Maybe instance
@see #retry()
@see <a href="http://reactivex.io/documentation/operators/retry.html">ReactiveX operators documentation: Retry</a>