reactor-core/src/main/java/reactor/core/publisher/Mono.java
public final Mono<T> timeout(Duration timeout, Scheduler timer) {
		return timeout(timeout, null, timer);
	}
public final Mono<T> timeout(Duration timeout, Scheduler timer) {
		return timeout(timeout, null, timer);
	}
Signal a {@link TimeoutException} error in case an item doesn't arrive before the given period,
as measured on the provided {@link Scheduler}.

<p>
<img class="marble" src="doc-files/marbles/timeoutForMono.svg" alt="">

@param timeout the timeout before the onNext signal from this {@link Mono}
@param timer a time-capable {@link Scheduler} instance to run the delay on

@return an expirable {@link Mono}