@Test(expected = ValidationException.class)
public void testTupleClassAttrValidation() throws Exception
{

  String resourcePath = "/schemaTestTopology.json";
  InputStream is = this.getClass().getResourceAsStream(resourcePath);
  if (is == null) {
    fail("Could not load " + resourcePath);
  }
  StringWriter writer = new StringWriter();
  IOUtils.copy(is, writer);
  JSONObject json = new JSONObject(writer.toString());
  //removing schema so that validation fails
  json.getJSONArray("streams").getJSONObject(0).remove("schema");
  Configuration conf = new Configuration(false);
  LogicalPlanConfiguration planConf = new LogicalPlanConfiguration(conf);
  LogicalPlan dag = planConf.createFromJson(json, "testLoadFromJson");
  dag.validate();
}