pitfall_10.java

interface Service {	
	Flux<String> observe();
	Mono<Void> save(String s);
}
class Foo {
	private final Service service;
	
	void longRunningProblem() {
		service.observe()
			.flatMap(service::save, 10)
			.subscribeOn(Schedulers.elastic())
			.subscribe();
	}
}