es
        @description Sort tree nodes and append theme back
      */
      sortNodes: function () {
        var el = this;
        var tree = el._refs.tree;
        var nodes = tree.children;
        var fragment = document.createDocumentFragment();
        var orderFragment = document.createDocumentFragment();

        var sortArray = [], elm;

        // Store object nodes into an array
        for (var i = 0; i < nodes.length; i++) {
          var node = nodes[i];
          sortArray.push([node.name, n