anchor.diff:  
   library spark_widgets.selector;
   
  -import 'dart:html' show MutationObserver, Node, Element;
  +import 'dart:html' show MutationRecord, MutationObserver, Node, Element;
   
   import 'package:polymer/polymer.dart';
   import "package:template_binding/template_binding.dart" show nodeBind;
  
positive.code:   @published bool notap = false;
    @published dynamic selectedModel = null;
  
    MutationObserver _observer;
  
    SparkSelector.created(): super.created();
  
    void ready() {
      super.ready();
      _observer =
          new MutationObserver((List mutations, MutationObserver observer) {
            updateSelected();
          });
      if (target == null) {
        target = this;
      }
    }
  
    List get items {
      List nodes = null;
      if (target == this) {
        nodes = ($['items'] as dynamic).getDistributedNodes();
  
negative.code:       }
      }
      // if no item found, the value itself is probably the index
      return (value is num) ? value : int.parse(value);
    }
  
    String valueForNode(Element node) =>
  