code: public final Mono<Void> then() {
  		@SuppressWarnings("unchecked")
  		Mono<Void> then = (Mono<Void>) new MonoIgnoreElements<>(this);
  		return Mono.onAssembly(then);
  	}
docs: Return a {@code Mono<Void>} that completes when this {@link Flux} completes.
  This will actively ignore the sequence and only replay completion or error signals.
  <p>
  <img class="marble" src="doc-files/marbles/thenForFlux.svg" alt="">
  <p>
  
  @reactor.discard This operator discards elements from the source.
  
  @return a new {@link Mono} representing the termination of this {@link Flux}