public void testQuery() {
   ExtObjectContainer oc = fixture().db();
   initGenericObjects();
   ReflectClass rc = getReflectClass(oc, PERSON_CLASSNAME);
   Assert.isNotNull(rc);
   // now query to make sure there are none left
   Query q = oc.query();
   q.constrain(rc);
   q.descend("surname").constrain("John");
   ObjectSet results = q.execute();
   Assert.isTrue(results.size() == 1);
 }