### Question:
NeovimTabpageRxWrapper implements NeovimTabpageRxApi { @Override public Single<Integer> getNumber() { return Single.fromFuture(neovimTabpageApi.getNumber()); } NeovimTabpageRxWrapper(NeovimTabpageApi neovimTabpageApi); @Override Tabpage get(); @Override Single<List<NeovimWindowRxApi>> getWindows(); @Override Single<NeovimWindowRxApi> getWindow(); @Override Single<Object> getVar(String name); @Override Completable setVar(String name, Object value); @Override Completable deleteVar(String name); @Override Single<Integer> getNumber(); @Override Single<Boolean> isValid();  }### Answer:
@Test public void delegatesNumberCall() { given(neovimTabpageApi.getNumber()).willReturn(CompletableFuture.completedFuture(5)); neovimTabpageRxWrapper.getNumber() .test() .assertComplete() .assertNoErrors() .assertValue(5); verify(neovimTabpageApi).getNumber(); }