anchor.diff:          callbackDone();
         });
   
  -    it.add({'id': 42});
  +    it.add(new TestHipsterModel());
     });
   
     new DARTest().run();
  
positive.code: 
    group('HipsterCollection fetch() callback', () {
      callbackSync(method, model, [options]) {
        print("[sync] $method / $model");
        options['onLoad']([]);
        callbackDone();
      }
  
negative.code: #import('lib/dartest/dartest.dart');
  
  #import("../public/scripts/HipsterCollection.dart");
  #import("../public/scripts/HipsterModel.dart");
  #import("../public/scripts/HipsterSync.dart");
  
  
  class TestHipsterCollection extends HipsterCollection {
    String get url() => 'test.json';
  }
  
  class TestHipsterModel extends HipsterModel {
    TestHipsterModel() : super({});
  }
  
  main() {
  