anchor.diff:  ///
   /// <?code-excerpt "docs/lifecycle-hooks/lib/src/do_check_component.dart (ng-do-check)"?>
   /// ```dart
  -/// ngDoCheck() {
  +/// void ngDoCheck() {
   ///   if (hero.name != oldHeroName) {
   ///     changeDetected = true;
   ///     changeLog.add(
  
positive.code: ///   int count = 0;
  ///
  ///   @override
  ///   ngOnInit() {
  ///     _onlineUserSub = onlineUsers.listen((count) => this.count = count);
  ///   }
  ///
  ///   @override
  ///   ngOnDestroy() {
  ///     _onlineUserSub.cancel();
  ///   }
  /// }
  
negative.code: ///   @ContentChild(ChildComponent)
  ///   ChildComponent contentChild;
  ///
  ///   @override
  ///   void ngAfterContentInit() {
  ///     // contentChild is set after the content has been initialized
  ///     _logIt('AfterContentInit');
  ///     _doSomething();
  ///   }
  ///
  ///   @override
  ///   void ngAfterContentChecked() {
  ///     // contentChild is updated after the content has been checked
  ///     if (_prevHero == contentChild?.hero) {
  ///       _logIt('AfterContentChecked (no change)');
  