@Override
    public Set<Output> loadByIds(Collection<String> ids) {
        final DBQuery.Query query = DBQuery.in(OutputImpl.FIELD_ID, ids);
        try (org.mongojack.DBCursor<OutputImpl> dbCursor = coll.find(query)) {
            return ImmutableSet.copyOf((Iterable<? extends Output>) dbCursor);
        }
    }
@Test
    @MongoDBFixtures("OutputServiceImplTest.json")
    public void loadByIdsReturnsRequestedOutputs() {
        assertThat(outputService.loadByIds(ImmutableSet.of())).isEmpty();
        assertThat(outputService.loadByIds(ImmutableSet.of("54e300000000000000000000"))).isEmpty();
        assertThat(outputService.loadByIds(ImmutableSet.of("54e3deadbeefdeadbeef0001", "54e300000000000000000000"))).hasSize(1);
        assertThat(outputService.loadByIds(ImmutableSet.of("54e3deadbeefdeadbeef0001", "54e3deadbeefdeadbeef0002", "54e300000000000000000000"))).hasSize(2);
    }