get selectedItems() {
      var indexes = this.selectionModel.selectedIndexes;
      var dataModel = this.dataModel;
      if (dataModel) {
        return indexes.map(function(i) {
          return dataModel.item(i);
        });
      }
      return [];
    }
Convenience alias for selectionModel.selectedItems
@type {!Array<cr.ui.ListItem>}