anchor.diff:      return this;
     }
   
  -  /**
  -   * @return {angular.core.Block}
  -   */
  -  remove() {
  +  Block remove() {
       bool preventDefault = false;
   
       Function removeDomElements = () {
  
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: /**
   * A Block is a fundamental building block of DOM. It is a chunk of DOM which
   * Can not be structural changed. It can only have its attributes changed.
   * A Block can have [BlockHole]s embedded in its DOM.  A [BlockHole] can
   * contain other [Block]s and it is the only way in which DOM can be changed
   * structurally.
   *
   * A [Block] is a collection of DOM nodes and [Directive]s for those nodes.
   *
   * A [Block] is responsible for instantiating the [Directive]s and for
   * inserting / removing itself to/from DOM.
   *
   * A [Block] can be created from [BlockFactory].
   *
   */
  class Block implements ElementWrapper {
  