/**
                             * A Widget to create groups of buttons
                             *
                             * @module button-group
                             * @since 3.5.0
                             */
                            
                            var CONTENT_BOX = "contentBox",
                                CLICK_EVENT = "click",
                                CLASS_NAMES = Y.ButtonCore.CLASS_NAMES;
                            
                            /**
                             * Creates a ButtonGroup
                             *
                             * @class ButtonGroup
                             * @extends Widget
                             * @param config {Object} Configuration object
                             * @constructor
                             */
                            function ButtonGroup() {
                                ButtonGroup.superclass.constructor.apply(this, arguments);
                            }
                            
                            /* ButtonGroup extends Widget */
                            Y.ButtonGroup = Y.extend(ButtonGroup, Y.Widget, {
                            
                                /**
                                 * @method renderUI
                                 * @description Creates a visual representation of the widget based on existing parameters.
                                 * @public
                                 */
                                renderUI: function() {
                                    this.getButtons().plug(Y.Plugin.Button);
                                },
                            
                                /**
                                 * @method bindUI
                                 * @description Hooks up events for the widget
                                 * @public
                                 */
                                bindUI: function() {
                                    var group = this,
                                        cb = group.get(CONTENT_BOX);
                            
                                    cb.delegate(CLICK_EVENT, group._handleClick, Y.ButtonGroup.BUTTON_SELECTOR, group);
                                    group.after('disabledChange', group._afterDisabledChange);
                                },
                            
                                _afterDisabledChange: function (e) {
                                    this.getButtons().each(e.newVal
                                        ? Y.ButtonCore.prototype.disable
                                        : Y.ButtonCore.prototype.enable
                                    );
                                },
                            
                                /**
                                 * @method getButtons
                                 * @description Returns all buttons inside this this button group
                                 * @public
                                 */
                                getButtons: function() {
                                    var cb = this.get(CONTENT_BOX);
                            
                                    return cb.all(Y.ButtonGroup.BUTTON_SELECTOR);
                                },
                            
                                /**
                                 * @method getSelectedButtons
                                 * @description Returns all Y.Buttons instances that are selected
                                 * @public
                                 */
                                getSelectedButtons: function() {
                                    var group = this,
                                        selected = [],
                                        buttons = group.getButtons(),
                                        selectedClass = ButtonGroup.CLASS_NAMES.SELECTED;
                            
                                    buttons.each(function(node){
                                        if (node.hasClass(selectedClass)){
                                            selected.push(node);
                                        }
                                    });
                            
                                    return selected;
                                },
                            
                                /**
                                 * @method getSelectedValues
                                 * @description Returns the values of all Y.Button instances that are selected
                                 * @public
                                 */
                                getSelectedValues: function() {
                                    var selected = this.getSelectedButtons(),
                                        values = [],
                                        value;
                            
                                    Y.Array.each(selected, function(node){
                                        value = node.getContent();
                                        values.push(value);
                                    });
                            
                                    return values;
                                },
                            
                                /**
                                 * @method _handleClick
                                 * @description A delegated click handler for when any button is clicked in the content box
                                 * @param e {Object} An event object
                                 * @private
                                 */
                                _handleClick: function(e){
                                    var group = this,
                                        clickedNode = e.target.ancestor('.' + ButtonGroup.CLASS_NAMES.BUTTON, true),
                                        type = group.get('type'),
                                        selectedClass = ButtonGroup.CLASS_NAMES.SELECTED,
                                        isSelected = clickedNode.hasClass(selectedClass),
                                        buttons;
                            
                                    // TODO: Anything for 'push' groups?
                                    if (type === 'checkbox') {
                                        clickedNode.toggleClass(selectedClass, !isSelected);
                                        /**
                                         * @event selectionChange
                                         * @description fires when any button in the group changes its checked status
                                         * @param {Event} the event object. It contains an "originEvent" property
                                         * linking to the original DOM event that triggered the selection change
                                         */
                                        group.fire('selectionChange', {originEvent: e});
                                    }
                                    else if (type === 'radio' && !isSelected) {
                                        buttons = group.getButtons(); // Todo: getSelectedButtons()? Need it to return an arraylist then.
                                        buttons.removeClass(selectedClass);
                                        clickedNode.addClass(selectedClass);
                                        group.fire('selectionChange', {originEvent: e});
                                    }
                                }
                            
                            }, {
                                // Y.ButtonGroup static properties
                            
                                /**
                                 * The identity of the widget.
                                 *
                                 * @property NAME
                                 * @type {String}
                                 * @default 'buttongroup'
                                 * @readOnly
                                 * @protected
                                 * @static
                                 */
                                NAME: 'buttongroup',
                            
                                /**
                                 * Static property used to define the default attribute configuration of
                                 * the Widget.
                                 *
                                 * @property ATTRS
                                 * @type {Object}
                                 * @protected
                                 * @static
                                 */
                                ATTRS: {
                            
                                    /**
                                     * @attribute type
                                     * @type String
                                     */
                                    type: {
                                        writeOnce: 'initOnly',
                                        value: 'radio'
                                    }
                                },
                            
                                /**
                                 * List of class names to use for ButtonGroups
                                 *
                                 * @property CLASS_NAMES
                                 * @type {Object}
                                 * @static
                                 */
                                CLASS_NAMES: CLASS_NAMES,
                            
                                /**
                                 * Selector used to find buttons inside a ButtonGroup
                                 * @property BUTTON_SELECTOR
                                 * @type {String}
                                 */
                                BUTTON_SELECTOR: "button, input[type=button], input[type=reset], input[type=submit], input[type=radio], input[type=checkbox]"
                            });