Project Reactor (WebFlux) Context 관련 테스트 방법

        Mono<Integer> mono = Mono.just(1)
                .subscriberContext(Context.of("key", "value"));

        StepVerifier.create(mono)
                .expectAccessibleContext()
                .contains("key", "value")
                .then()
                .expectNext(1)
                .verifyComplete();