/**
                             * Provides standard module support for toggle visibility method through an
                             * extension.
                             * @module aui-widget-toggle
                             */
                            
                            /**
                             * Widget extension, which can be used to add toggle visibility support to the
                             * base Widget class, through the [Base.build](Base.html#method_build)
                             * method.
                             *
                             * @class A.WidgetToggle
                             * @param {Object} The user configuration object
                             */
                            
                            function WidgetToggle() {}
                            
                            WidgetToggle.prototype = {
                                /**
                                 * Toggles widget visibility.
                                 *
                                 * @method toggle
                                 * @param {Boolean} visible Force the widget to be visible.
                                 */
                                toggle: function(visible) {
                                    var instance = this;
                            
                                    if (!A.Lang.isBoolean(visible)) {
                                        visible = !instance.get('visible');
                                    }
                            
                                    return instance.set('visible', visible);
                                }
                            };
                            
                            A.WidgetToggle = WidgetToggle;