reactor-core/src/main/java/reactor/core/publisher/Flux.java
public final <U> Flux<T> timeout(Publisher<U> firstTimeout) {
		return timeout(firstTimeout, t -> never());
	}
public final <U> Flux<T> timeout(Publisher<U> firstTimeout) {
		return timeout(firstTimeout, t -> never());
	}
Signal a {@link TimeoutException} in case the first item from this {@link Flux} has
not been emitted before the given {@link Publisher} emits.

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

@param firstTimeout the companion {@link Publisher} that will trigger a timeout if
emitting before the first signal from this {@link Flux}

@param <U> the type of the timeout Publisher

@return a {@link Flux} that can time out if the first item does not come before
a signal from a companion {@link Publisher}