anchor.diff:  
     @override
     SelectableGetter<T> getSelectable;
  -
  -  @override
  -  SelectableGetter<TreeNode> getTreeNodeSelectable;
   
     @override
     bool supportsSelectAll = true;
  
positive.code: 
  import 'package:observable/observable.dart';
  import 'package:angular_components/model/selection/select.dart';
  import 'package:angular_components/model/tree/tree_model.dart';
  
  import 'selection_model.dart';
  
  
negative.code:   }
  }
  
  /// MultiSelection model that supports "All across pages" selection, that marks
  /// user intent to do bulk action on all entries (even those not currently
  /// visible in a given context).
  abstract class TableSelectionModel<T> extends BaseTableSelectionModel<T>
      implements SelectableWithComposition<T>, MultiSelectionModel<T> {
    factory TableSelectionModel(
        {KeyProvider<T> keyProvider,
        SelectableGetter<T> getSelectable,
  