@Override
    public Set<Input> findByIds(Collection<String> ids) {
        final Set<ObjectId> objectIds = ids.stream()
                .map(ObjectId::new)
                .collect(Collectors.toSet());

        final DBObject query = BasicDBObjectBuilder.start()
                .push(InputImpl.FIELD_ID)
                .append("$in", objectIds)
                .get();
        final Stream<InputImpl> inputStream = query(InputImpl.class, query).stream()
                .map(o -> createFromDbObject(o));
        return inputStream
                .collect(Collectors.toSet());
    }
@Test
    @MongoDBFixtures("InputServiceImplTest.json")
    public void findByIdsReturnsRequestedInputs() {
        assertThat(inputService.findByIds(ImmutableSet.of())).isEmpty();
        assertThat(inputService.findByIds(ImmutableSet.of("54e300000000000000000000"))).isEmpty();
        assertThat(inputService.findByIds(ImmutableSet.of("54e3deadbeefdeadbeef0001"))).hasSize(1);
        assertThat(inputService.findByIds(ImmutableSet.of("54e3deadbeefdeadbeef0001", "54e3deadbeefdeadbeef0003"))).hasSize(2);
        assertThat(inputService.findByIds(ImmutableSet.of("54e3deadbeefdeadbeef0001", "54e3deadbeefdeadbeef0003", "54e300000000000000000000"))).hasSize(2);
    }