anchor.diff:  }
   
   /**
  - * BlockCache is used to cache the compilation of templates into Blocks.
  + * BlockCache is used to cache the compilation of templates into [Block]s.
    * It can be used synchronously if HTML is known or asynchronously if the
    * template HTML needs to be looked up from the URL.
    */
  
positive.code: Symbol _SHADOW = new Symbol('SHADOW_INJECTOR');
  
  /**
  * ElementWrapper is an interface for Blocks and BlockHoles. Its purpose is to
  * allow treating Block and BlockHole under same interface so that Blocks can
  * be added after BlockHole.
  */
  abstract class ElementWrapper {
    List<dom.Node> elements;
  
negative.code:     return this;
    }
  
    Block remove() {
      bool preventDefault = false;
  
      Function removeDomElements = () {
  