List<Region> regions = Lists.newArrayList();
Region item = new RegionImpl("1111L");
regions.add(item);
page.setRegions(regions);
expect(template.findOne(new Query(Criteria.where("regions").elemMatch(Criteria.where("_id").is("1111L"))))).andReturn(page);
expect(template.save(isA(Page.class))).andReturn(page);
replay(template);
Region result = repo.save(item);
assertThat(result.getId(), is(equalTo("1111L")));