@Override
    public Set<GrokPattern> bulkLoad(Collection<String> patternIds) {
        final DBCursor<GrokPattern> dbCursor = dbCollection.find(DBQuery.in("_id", patternIds));
        return ImmutableSet.copyOf((Iterator<GrokPattern>) dbCursor);
    }
@Test
    @MongoDBFixtures("MongoDbGrokPatternServiceTest.json")
    public void bulkLoad() {
        final List<String> idList = ImmutableList.of(
                "56250da2d400000000000001",
                "56250da2d400000000000002",
                "56250da2d4000000deadbeef");

        final Set<GrokPattern> grokPatterns = service.bulkLoad(idList);
        assertThat(grokPatterns)
                .hasSize(2)
                .contains(
                        GrokPattern.create("56250da2d400000000000001", "Test1", "[a-z]+", null),
                        GrokPattern.create("56250da2d400000000000002", "Test2", "[a-z]+", null));
    }