anchor.diff:    }
   
     Map toMap() {
  -    var res = new Map.from(_data);
  +    var res = {};
       _data.forEach((k,v) {
  -
  +      if (v is ConfigMap) {
  +        res[k] = v.toMap();
  +      } else {
  +        res[k] = this[k];
  +      }
       });
  +    return res;
     }
   
     ConfigMap.config(ConfigMap this.root, Map this._data);
  
positive.code: 
  class ComputedValue {
    final _computation;
    bool _evaluated;
    dynamic _value;
    ComputedValue(dynamic this._computation(ConfigMap config));
  
  
negative.code:    * Throws [ArgumentError] if configuration with [name] does not exists.
     */
    Map get(name) {
      if (!_configurations.containsKey(name)) throw new ArgumentError("Configuration does not exist");
      var config = _configurations[name];
      if (config["parent"] == null) {
        return config["configMap"].toMap();
      } else {
        return mergeMaps(get(config["parent"]), config["configMap"]);
      }
    }
  }