anchor.diff:      test("send change-request.", () {
         // given
         idGenerator.when(callsTo('next')).alwaysReturn('prefix-1');
  -      months = new Subscription('months', connection, 'author', idGenerator);
         january = new Data.from({'name': 'January', 'order': 1});
  -
  -      // when
  -      months.collection.add(january);
  +      collection.add(january);
  +      months = new Subscription.config('months', collection, connection,
  +          communicator, 'author', idGenerator);
  +
  +      // when
  +      months.start();
         january.addAll({'length': 31});
   
         // then
  
positive.code: 
  class ConnectionMock extends Mock implements Connection {}
  class IdGeneratorMock extends Mock implements IdGenerator {}
  
  void main() {
    group("Subscriber", () {
  
negative.code:     test("send remove-request.", () {
        // given
        idGenerator.when(callsTo('next')).alwaysReturn('prefix-1');
        january = new Data.from({'_id': '12', 'name': 'January', 'order': 1});
        collection.add(january);
        months = new Subscription.config('months', collection, connection,
            communicator, 'author', idGenerator);
  
        // when
        months.start();
        months.collection.remove(january);
  
        // then
        var request = connection.getLogs().first.args[0]();
        expect(request.type, equals("sync"));
        expect(request.args, equals({"action": "remove", "collection": "months",
                                     "_id": "12", "author": "author"}));
      });
  
    });
  }
  