anchor.diff:        return "list";
       }
     }
  +
  +  @HostBinding('attr.aria-multiselectable')
  +  String get hostMultiselectable => '$showFlatCheck';
  +
  +  @HostBinding('attr.aria-readonly')
  +  String get hostReadonly => '$showFlatList';
   }
  
positive.code:   bool get showFlatRadio => !showFlatList && !showFlatCheck;
  
    /// The ARIA role to use for the host element.
    String get role {
      if (supportsHierarchy) {
        return "tree";
  
negative.code:     NgFor,
      NgIf
    ],
    viewProviders: const [
      const Provider(MaterialTreeRoot, useExisting: MaterialTreeComponent)
    ],
  