code: public final Flux<T> concatWith(Publisher<? extends T> other) {
  		if (this instanceof FluxConcatArray) {
  			@SuppressWarnings({ "unchecked" })
  			FluxConcatArray<T> fluxConcatArray = (FluxConcatArray<T>) this;
  
  			return fluxConcatArray.concatAdditionalSourceLast(other);
  		}
  		return concat(this, other);
  	}
docs: Concatenate emissions of this {@link Flux} with the provided {@link Publisher} (no interleave).
  <p>
  <img class="marble" src="doc-files/marbles/concatWithForFlux.svg" alt="">
  
  @param other the {@link Publisher} sequence to concat after this {@link Flux}
  
  @return a concatenated {@link Flux}