@Test
  public void testEmptyObject() throws Exception {
    EmptyObject emptyObject = new EmptyObject();
    region.put("port", emptyObject);
    String queryResult = queryEngine.queryForJsonResult(QUERY_1, 0, queryResultSetLimit,
        queryCollectionsDepth);
    String expectedResult = "{\"result\":[[\"org.apache.geode.management.model.EmptyObject\",{}]]}";
    assertThat(queryResult).isEqualToIgnoringWhitespace(expectedResult);

    // If not correct JSON format this will throw a JSONException
    new ObjectMapper().readTree(queryResult);
  }
Tests a model where Objects have a circular reference with their class types. e.g. Order1--
Has--> Items each Item --Has --> OrderN where (OrderN != Order1)
geode-core/src/integrationTest/java/org/apache/geode/management/DataQueryEngineIntegrationTest.java