anchor.diff:      return true;
     }
   
  -  /**
  -   * Returns true if the scope is still attached to the [RootScope].
  -   */
  +  /// true when the scope is still attached to the [RootScope].
     bool get isAttached => !isDestroyed;
   
     // TODO(misko): WatchGroup should be private.
  
positive.code:   /**
     * Use [watch] to set up change detection on an pre-parsed AST.
     *
     * * [ast] The pre-parsed AST.
     * * [reactionFn]: The function executed when a change is detected.
     * * [canChangeModel]: Whether or not the [reactionFn] can change the model.
     */
  
negative.code: 
    static pad(String str, int size) => _PAD_.substring(0, max(size - str.length, 0)) + str;
  
    String _ms(num value) => '${pad(_nfDec.format(value), 9)} ms';
    String _us(num value) => _ms(value / 1000);
    String _tally(num value) => '${pad(_nfInt.format(value), 6)}';
  
    /**
     * Emit a message based on the phase and state of stopwatches.
  