reactor-core/src/main/java/reactor/core/publisher/Mono.java
public final <R> Flux<R> flatMapMany(Function<? super T, ? extends Publisher<? extends R>> mapperOnNext,
			Function<? super Throwable, ? extends Publisher<? extends R>> mapperOnError,
			Supplier<? extends Publisher<? extends R>> mapperOnComplete) {
		return flux().flatMap(mapperOnNext, mapperOnError, mapperOnComplete);
	}
public final <R> Flux<R> flatMapMany(Function<? super T, ? extends Publisher<? extends R>> mapperOnNext,
			Function<? super Throwable, ? extends Publisher<? extends R>> mapperOnError,
			Supplier<? extends Publisher<? extends R>> mapperOnComplete) {
		return flux().flatMap(mapperOnNext, mapperOnError, mapperOnComplete);
	}
Transform the signals emitted by this {@link Mono} into signal-specific Publishers,
then forward the applicable Publisher's emissions into the returned {@link Flux}.

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

@param mapperOnNext the {@link Function} to call on next data and returning a sequence to merge
@param mapperOnError the {@link Function} to call on error signal and returning a sequence to merge
@param mapperOnComplete the {@link Function} to call on complete signal and returning a sequence to merge
@param <R> the type of the produced inner sequence

@return a new {@link Flux} as the sequence is not guaranteed to be single at most

@see Flux#flatMap(Function, Function, Supplier)