anchor.diff:          } else {
             this.selected = s;
           }
  -        this.asyncFire('polymer-activate', detail: {'item': item });
  +        this.asyncFire('polymer-activate', detail: {
  +          'item': item
  +        });
         }
       }
     }
  
positive.code:     //for a matching variable or getter.
      try {
        return mirror.getField(new Symbol('${this.valueattr}')).reflectee;
      }catch(e){
        return node.attributes[this.valueattr];
      };
    }
  
    // events fired from <polymer-selection> object
  
negative.code:       nodes = (this.$['items'] as dom.ContentElement).getDistributedNodes();
      }
  
      return nodes.where((dom.Element e) {
        return e != null && e.localName != 'template';
      }).toList();
    }
  