code: function (from, to) {
      if (to === undefined) {
        to = eachView.numItems - 1;
      }
  
      for (var i = from; i <= to; i++) {
        var view = eachView._domrange.members[i].view;
        view._scopeBindings['@index'].set(i);
      }
    }
docs: update the @index value in the scope of all subviews in the range