RxJava2Adapter { public static Mono<Void> completableToMono(Completable source) { return new CompletableAsMono(source); } RxJava2Adapter(); static Flux<T> flowableToFlux(Flowable<T> source); static Flowable<T> fluxToFlowable(Flux<T> source); static Flowable<T> monoToFlowable(Mono<T> source); static Completable monoToCompletable(Mono<?> source); static Mono<Void> completableToMono(Completable source); static Single<T> monoToSingle(Mono<T> source); static Mono<T> singleToMono(Single<T> source); static Flux<T> observableToFlux(Observable<T> source, BackpressureStrategy strategy); static Observable<T> fluxToObservable(Flux<T> source); static Mono<T> maybeToMono(Maybe<T> source); static Maybe<T> monoToMaybe(Mono<T> source);  }
@Test public void completableToMono() { Mono<Void> m = Completable.complete() .to(RxJava2Adapter::completableToMono); StepVerifier.create(m) .expectComplete() .verify(); }