public static Function<Flux<Long>, Publisher<?>> instant() {
        return iterations -> iterations
            .flatMap(iteration -> Mono
                .just(0L)
                .doOnSubscribe(logDelay(Duration.ZERO)), 1);
    }
public static Function < Flux < Long > , Publisher < ? > > instant ( ) { return iterations -> iterations . flatMap ( iteration -> Mono . just ( 0L ) . doOnSubscribe ( logDelay ( Duration . ZERO ) ) , 1 ) ; }
Implements an instant (no delay) for use with {@link Mono#repeatWhenEmpty(Function)}

@return an instant (no delay) {@link Publisher}