anchor.diff:      HttpRequest r = httpRequestFactory();
       _addResponseHandler(r, onSuccess);
   
  -    String id = params['id'];
  -    String deleteUrl = '${url}/${id}';
  -
  -    r.open('DELETE', deleteUrl, true);
  +    r.open('DELETE', _singleItemUrl(params), true);
       r.send();
     }
  +
  +  String _singleItemUrl(Map<String, String> params) => "$url/${params['id']}";
   
     void _addResponseHandler(HttpRequest request, void onSuccess(Object data)) {
       request.on.load.add((event) {
  
positive.code:     HttpRequest r = httpRequestFactory();
      _addResponseHandler(r, onSuccess);
  
      String id = params['id'];
      String getUrl = '${url}/${id}';
  
      r.open('GET', getUrl, true);
      r.send();
    }
  
  
negative.code:     HttpRequest r = httpRequestFactory();
      _addResponseHandler(r, onSuccess);
  
      r.open('PUT', _singleItemUrl(params), true);
      r.send();
    }
  
  