### Question:
DropWhileStageFactory implements ProcessingStageFactory<Stage.DropWhile> { @Override public <I, O> ProcessingStage<I, O> create(Engine engine, Stage.DropWhile stage) { Predicate<I> predicate = Casts.cast(stage.getPredicate()); return Casts.cast(new TakeWhile<>(predicate)); }  @Override ProcessingStage<I, O> create(Engine engine, Stage.DropWhile stage);  }### Answer:
@Test public void create() throws ExecutionException, InterruptedException { Multi<Integer> publisher = Multi.createFrom().items(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) .emitOn(executor); List<Integer> list = ReactiveStreams.fromPublisher(publisher).dropWhile(i -> i < 6).toList().run() .toCompletableFuture().get(); assertThat(list).hasSize(5).containsExactly(6, 7, 8, 9, 10); }
@SuppressWarnings("ConstantConditions") @Test public void createWithoutStage() { assertThrows(NullPointerException.class, () -> factory.create(null, null)); }
@Test public void createWithoutPredicate() { assertThrows(NullPointerException.class, () -> factory.create(null, () -> null)); }