demo/amd/rjs/output/unified/marionette-build.js
function() {
      var models = this._filteredSortedModels();
  
      // check for any changes in sort order of views
      var orderChanged = _.find(models, function(item, index) {
        var view = this.children.findByModel(item);
        return !view || view._index !== index;
      }, this);
  
      if (orderChanged) {
        this.resortView();
      }
    }
function() {
      var models = this._filteredSortedModels();
  
      // check for any changes in sort order of views
      var orderChanged = _.find(models, function(item, index) {
        var view = this.children.findByModel(item);
        return !view || view._index !== index;
      }, this);
  
      if (orderChanged) {
        this.resortView();
      }
    }
Internal method. This checks for any changes in the order of the collection. If the index of any view doesn't match, it will render.