es
        return treeNode;
      },
      /*
        @function (private) _clean
        @description Remove tree nodes and their references
      */
      clean: function (cleanRefs) {
        var el = this;
        var tree = el._refs.tree;
        // Remove current children
        while (tree.hasChildNodes()) {
          tree.removeChild(tree.lastChild);
        }
        // Reset tree nodes
        if(cleanRefs) {
          el.nodes = {};
        }
      },
      /*
        @function (private) _copyPro