code: public final <E extends Throwable> Flux<T> onErrorMap(Class<E> type,
  			Function<? super E, ? extends Throwable> mapper) {
  		@SuppressWarnings("unchecked")
  		Function<Throwable, Throwable> handler = (Function<Throwable, Throwable>)mapper;
  		return onErrorMap(type::isInstance, handler);
  	}
docs: Transform an error emitted by this {@link Flux} by synchronously applying a function
  to it if the error matches the given type. Otherwise let the error pass through.
  <p>
  <img class="marble" src="doc-files/marbles/onErrorMapWithClassPredicateForFlux.svg" alt="">
  
  @param type the class of the exception type to react to
  @param mapper the error transforming {@link Function}
  @param <E> the error type
  
  @return a {@link Flux} that transforms some source errors to other errors