public Optional<ContentPack> findByIdAndRevision(ModelId id, int revision) {
        final DBQuery.Query query = DBQuery.is(Identified.FIELD_META_ID, id).is(Revisioned.FIELD_META_REVISION, revision);
        return Optional.ofNullable(dbCollection.findOne(query));
    }
@Test
    @MongoDBFixtures("ContentPackPersistenceServiceTest.json")
    public void findByIdAndRevisionWithInvalidRevision() {
        final Optional<ContentPack> contentPack = contentPackPersistenceService.findByIdAndRevision(ModelId.of("dcd74ede-6832-4ef7-9f69-deadbeef0000"), 42);

        assertThat(contentPack).isEmpty();
    }