anchor.diff:     * 3. processing the DOM read queue
      * 4. repeat steps 1 and 3 (not 2) until queues are empty
      *
  -   * ##assert
  +   * ## `STATE_FLUSH_ASSERT`
      *
      * Optionally if Dart assert is on, verify that flush reaction functions did not make any changes
      * to model and throw error if changes detected.
  -   *
      */
     String get state => _state;
   
  
positive.code:   var emit = false;
  
    ScopeStatsConfig();
    ScopeStatsConfig.enabled() {
      emit = true;
    }
  }
  /**
   *
   * Every Angular application has exactly one RootScope. RootScope extends Scope, adding
   * services related to change detection, async unit-of-work processing, and DOM read/write queues.
   * The RootScope can not be destroyed.
  
negative.code: }
  
  /**
   * [Scope] represents a collection of [watch]es [observer]s, and a [context] for the watchers,
   * observers and [eval]uations. Scopes structure loosely mimics the DOM structure. Scopes and
   * [View]s are bound to each other. As scopes are created and destroyed by [ViewFactory] they are
   * responsible for change detection, change processing and memory management.
   */
  class Scope {
    final String id;
    int _childScopeNextId = 0;
  
    /// The default execution context for [watch]es [observe]ers, and [eval]uation.
    final context;
  
    /// The [RootScope] of the application.
    final RootScope rootScope;
  
    Scope _parentScope;
  
    Scope get parentScope => _parentScope;
  
    final ScopeStats _stats;
  