public Stream<DTO> streamAll() {
        return streamQuery(DBQuery.empty());
    }
@Test
    public void streamAll() {
        dbService.save(newDto("hello1"));
        dbService.save(newDto("hello2"));
        dbService.save(newDto("hello3"));
        dbService.save(newDto("hello4"));

        try (final Stream<TestDTO> cursor = dbService.streamAll()) {
            assertThat(cursor.collect(Collectors.toList()))
                    .hasSize(4)
                    .extracting("title")
                    .containsExactly("hello1", "hello2", "hello3", "hello4");
        }
    }