/**
                            @module tree
                            @submodule tree-labelable
                            **/
                            
                            /**
                            `Tree.Node` extension that adds baked in support for labels like you might see
                            in a treeview or menu.
                            
                            **Security note:** The label is stored in raw, unescaped form. If you choose to
                            render the label as HTML, be sure to escape it first with `Y.Escape.html()`
                            unless you actually intend to render raw HTML contained in the label.
                            
                            @class Tree.Node.Labelable
                            @constructor
                            @param {Tree} tree `Tree` instance with which this node should be associated.
                            @param {Object} [config] Configuration hash.
                                @param {String} [config.label=''] Label for this node.
                            @extensionfor Tree.Node
                            **/
                            
                            function NodeLabelable(tree, config) {
                                this._serializable = this._serializable.concat('label');
                            
                                if ('label' in config) {
                                    this.label = config.label;
                                }
                            }
                            
                            NodeLabelable.prototype = {
                                /**
                                Label for this node.
                            
                                **Security note:** The label is stored in raw, unescaped form. If you choose
                                to render the label as HTML, be sure to escape it first with
                                `Y.Escape.html()` unless you actually intend to render raw HTML contained in
                                the label.
                            
                                @property {String} label
                                @default ''
                                **/
                                label: ''
                            };
                            
                            Y.Tree.Node.Labelable = NodeLabelable;