anchor.diff:  /// )
   /// class ParentComponent implements AfterViewInit {
   ///   @ViewChild(ChildComponent)
  -///   ChildComponentviewChild;
  +///   ChildComponent viewChild;
   ///
   ///   ParentComponent() {
   ///     // viewChild is not initialized yet
  
positive.code: /// Use [KeyValueDiffers] and [IterableDiffers] to add your custom check
  /// mechanisms.
  ///
  /// ## Example
  ///
  /// In the following example `ngDoCheck` uses an [IterableDiffers] to detect the
  /// updates to the array `list`:
  
negative.code: /// Implement this interface to get notified when your component's view has been
  /// fully initialized.
  ///
  /// ### Example
  ///
  /// ```dart
  /// @Component(selector: 'child-cmp', template: '{{where}} child')
  