anchor.diff:  
     // Handle list
     if (jsObject is Iterable) {
  -    return jsObject.map(dartify).toList();
  +    return jsObject.map((item) => dartify(item, customDartify)).toList();
     }
   
     var jsDate = js.dartifyDate(jsObject);
  
positive.code:   }
  
    if (dartObject is Iterable) {
      return jsifyList(dartObject);
    }
  
    if (dartObject is Map) {
  
negative.code: }
  
  // Converts an Iterable into a JS Array
  dynamic jsifyList(Iterable list, [Object Function(Object object) customJsify]) {
    return js.toJSArray(list.map((item) => jsify(item, customJsify)).toList());
  }
  
  // Returns the JS implementation from Dart Object.
  