reactor-core/src/main/java/reactor/core/publisher/Flux.java
public final <V> Flux<V> thenMany(Publisher<V> other) {
		if (this instanceof FluxConcatArray) {
			@SuppressWarnings({ "unchecked" })
			FluxConcatArray<T> fluxConcatArray = (FluxConcatArray<T>) this;
			return fluxConcatArray.concatAdditionalIgnoredLast(other);
		}

		@SuppressWarnings("unchecked")
		Flux<V> concat = (Flux<V>)concat(ignoreElements(), other);
		return concat;
	}
public final <V> Flux<V> thenMany(Publisher<V> other) {
		if (this instanceof FluxConcatArray) {
			@SuppressWarnings({ "unchecked" })
			FluxConcatArray<T> fluxConcatArray = (FluxConcatArray<T>) this;
			return fluxConcatArray.concatAdditionalIgnoredLast(other);
		}

		@SuppressWarnings("unchecked")
		Flux<V> concat = (Flux<V>)concat(ignoreElements(), other);
		return concat;
	}
Let this {@link Flux} complete then play another {@link Publisher}.
<p>
In other words ignore element from this flux and transform the completion signal into a
{@code Publisher<V>} that will emit elements from the provided {@link Publisher}.
<p>
<img class="marble" src="doc-files/marbles/thenManyForFlux.svg" alt="">

@reactor.discard This operator discards elements from the source.

@param other a {@link Publisher} to emit from after termination
@param <V> the element type of the supplied Publisher

@return a new {@link Flux} that emits from the supplied {@link Publisher} after
this Flux completes.