code: public static <T> FluxProcessor<Publisher<? extends T>, T> switchOnNext() {
  		UnicastProcessor<Publisher<? extends T>> emitter = UnicastProcessor.create();
  		FluxProcessor<Publisher<? extends T>, T> p = FluxProcessor.wrap(emitter, switchOnNext(emitter));
  		return p;
  	}
docs: Build a {@link FluxProcessor} whose data are emitted by the most recent emitted {@link Publisher}.
  The {@link Flux} will complete once both the publishers source and the last switched to {@link Publisher} have
  completed.
  
  <p>
  <img class="marble" src="https://raw.githubusercontent.com/reactor/reactor-core/v3.1.3.RELEASE/src/docs/marble/switchonnext.png" alt="">
  
  @param <T> the produced type
  @return a {@link FluxProcessor} accepting publishers and producing T