anchor.diff:        '.hero {background: LightYellow; padding: 8px; margin-top: 8px}',
         'p {background: Yellow; padding: 8px; margin-top: 8px}'
       ])
  -class DoCheckComponent implements DoCheck, OnChanges {
  +class DoCheckComponent implements DoCheck {
     @Input()
     Hero hero;
     @Input()
  
positive.code: // #docregion
  import 'dart:convert';
  
  import 'package:angular2/core.dart';
  
  class Hero {
  
negative.code:   }
    // #enddocregion ng-do-check
  
    void reset() {
      changeDetected = true;
      changeLog.clear();
  