### Question:
ChangesBus { @Nullable public Flowable<T> asFlowable() { return rxChangesBus != null ? rxChangesBus.asFlowable() : null; } ChangesBus(boolean rxJavaIsInTheClassPath); void onNext(@NonNull T next); @Nullable Flowable<T> asFlowable();  }### Answer:
@Test public void asFlowableShouldNotReturnNullIfRxJavaInClassPath() { ChangesBus<String> changesBus = new ChangesBus<String>(true); assertThat(changesBus.asFlowable()).isNotNull(); }
@Test public void asFlowableShouldReturnNullIfRxJavaIsNotInTheClassPath() { ChangesBus<String> changesBus = new ChangesBus<String>(false); assertThat(changesBus.asFlowable()).isNull(); }