@Udf
  public List<String> items(@UdfParameter final String jsonItems) {
    if (jsonItems == null) {
      return null;
    }


    final List<JsonNode> objectList = UdfJsonMapper.readAsJsonArray(jsonItems);
    final List<String> res = new ArrayList<>();
    objectList.forEach(jsonObject -> {
      res.add(jsonObject.toString());
    });
    return res;
  }
@Test
  public void shouldSupportJsonIntegerType() {
    assertEquals(ImmutableList.of("1","2","3"), udf.items("[1, 2, 3]"));
  }