code: public final <R> Flux<R> handle(BiConsumer<? super T, SynchronousSink<R>> handler) {
  		if (this instanceof Fuseable) {
  			return onAssembly(new FluxHandleFuseable<>(this, handler));
  		}
  		return onAssembly(new FluxHandle<>(this, handler));
  	}
docs: Handle the items emitted by this {@link Flux} by calling a biconsumer with the
  output sink for each onNext. At most one {@link SynchronousSink#next(Object)}
  call must be performed and/or 0 or 1 {@link SynchronousSink#error(Throwable)} or
  {@link SynchronousSink#complete()}.
  
  @param handler the handling {@link BiConsumer}
  @param <R> the transformed type
  
  @reactor.errorMode This operator supports {@link #onErrorContinue(BiConsumer) resuming on errors} (including when
  fusion is enabled) when the {@link BiConsumer} throws an exception or if an error is signaled explicitly via
  {@link SynchronousSink#error(Throwable)}.
  
  @return a transformed {@link Flux}