WebClientUserService implements UserService { public Mono<User> save(User user) { return this.webClient.post() .uri(this.usersUrl) .syncBody(user) .retrieve() .bodyToMono(User.class); } WebClientUserService(WebClient webClient,
			@Value("${users-url}") String usersUrl); Mono<User> save(User user); Mono<User> findByEmail(String email); Mono<User> findById(String id);  }
@Test public void save() { }