anchor.diff:          requestHandler.registerDefaultHandler(pub.handleSyncRequest);
           connection = createLoopBackConnection(requestHandler);
   
  -        var _idGenerator = new IdGeneratorMock();
  -        subSender = new Subscription('a', connection, 'author1', _idGenerator, {});
  +        subSender = new Subscription('a', connection, 'author1', new IdGenerator('a'), {});
           sender = subSender.collection;
   
  -        subReceiver = new Subscription('a', connection, 'author2', _idGenerator, {});
  +        subReceiver = new Subscription('a', connection, 'author2', new IdGenerator('b'), {});
           receiver = subReceiver.collection;
  -        subReceiverb = new Subscription('b', connection, 'author3', _idGenerator, {});
  -        subReceiverc = new Subscription('c', connection, 'author4', _idGenerator, {});
  +        subReceiverb = new Subscription('b', connection, 'author3', new IdGenerator('c'), {});
  +        subReceiverc = new Subscription('c', connection, 'author4', new IdGenerator('d'), {});
   
           receiverb = subReceiverb.collection;
           receiverc = subReceiverc.collection;
  
positive.code: 
      Future.forEach(new List.filled(100000, null), (_) {
          print(i++);
          do{} while(!action());
  //        sender.where((d) => (d.containsKey('a') && d['a'] is Map && d['a']['a'] == 'hello'));
          print(receiver);
          bool end = false;
  
negative.code: 
    test('test random', () {
  
    var action = (){
      for (int i=0; i<5; i++) {
        Subscription toChangeSub = randomChoice([subSender, subReceiver]);
        makeRandomChange(toChangeSub.collection);
      }
    };
  
  //  var action = (){
  //    Subscription toChangeSub = randomChoice([subSender, subReceiver]);
  //    logger.fine('$toChangeSub');
  //    return makeRandomChange(toChangeSub.collection);
  //  };
  
    var makeExpects = () {
      expect(stripPrivateFieldsList(receiver),
  