@Test
  void projection() {
    // TODO: can't use InMemoryBackend because of circular dependency.
    RxJavaModelRepository repo = new RxJavaModelRepository(new FakeBackend(Flowable.just(ImmutableRxJavaModel.builder().id("id1").build())));
    repo.findAll()
            //.select(RxJavaModelCriteria.rxJavaModel.id)  TODO: FakeBackend does not support projections
            .limit(1)
            .offset(0)
            .fetch()
            .test()
            .awaitDone(1, TimeUnit.SECONDS)
            .assertValueCount(1);
  }
Validate the projections work with different types of facets (see {@link org.immutables.criteria.repository.Facet}).
criteria/rxjava2/test/org/immutables/criteria/repository/rxjava2/RxJavaTest.java