code: public final <E extends Throwable> Flux<T> onErrorResume(Class<E> type,
  			Function<? super E, ? extends Publisher<? extends T>> fallback) {
  		Objects.requireNonNull(type, "type");
  		@SuppressWarnings("unchecked")
  		Function<? super Throwable, Publisher<? extends T>> handler = (Function<?
  				super Throwable, Publisher<? extends T>>)fallback;
  		return onErrorResume(type::isInstance, handler);
  	}
docs: Subscribe to a fallback publisher when an error matching the given type
  occurs, using a function to choose the fallback depending on the error.
  <p>
  <img class="marble" src="doc-files/marbles/onErrorResumeForFlux.svg" alt="">
  
  @param type the error type to match
  @param fallback the function to choose the fallback to an alternative {@link Publisher}
  @param <E> the error type
  
  @return a {@link Flux} falling back upon source onError