anchor.diff:    });
   }
   
  +var longS = new List.filled(1000, 'a').join('');
  +
   test3(){
  -  var longS ='aaaaaaaaaaaabbbbbbbbbbcccccc';
       Map m = new Map.from({'a': {'a': longS, 'b': {'a' : longS, 'b': longS}}});
       for(int i=0; i<10000000000; i++){
         print(i);
  
positive.code: import "package:unittest/unittest.dart";
  import 'package:clean_data/clean_data.dart';
  import "dart:async";
  
  magicalTick(){
    new Timer.periodic(const Duration(milliseconds:1000), (t) {
  
negative.code:     if (level==0) {
        return m['value'] = 'a';
      } else {
        for (int i=0; i<10; i++) {
          var mm = new Map();
          m['$i'] = mm;
          enhance(mm, level - 1);
        }
      }
    }
  
    enhance2(Map m, num level){
      for (int i=0; i<40; i++) {
        if(level==0){
          m['$i'] = 'a';
        } else {
          var mm = new Map();
          m['$i'] = mm;
          enhance(mm, level - 1);
        }
      }
    }
  
  
  //  magicalTick();
    var m = {};
    enhance2(m, 5);
    print(m.toString().length);
    var s = new Stopwatch()..start();
    var a = cleanify(m);
  