/**
                             * A set of utility methods for Node to allow 'hiding'
                             * while still allowing screen readers access.
                             *
                             * @module aui-node-accessible
                             * @submodule aui-node-accessible
                             */
                            
                            var CSS_BOOTSTRAP_SR_ONLY = A.getClassName('sr-only');
                            
                            A.mix(A.Node.prototype, {
                            
                                /**
                                 * Hides the node, while still keeping it accessible by screen readers.
                                 *
                                 * @method hideAccessible
                                 */
                                hideAccessible: function() {
                                    this.addClass(CSS_BOOTSTRAP_SR_ONLY);
                            
                                    this.onceAfter(this.showAccessible, this, 'show');
                                },
                            
                                /**
                                 * Shows the node. Fires after the node-base `show` method to clean up nodes
                                 * which were hidden through the `hideAccessible` method.
                                 *
                                 * @method showAccessible
                                 */
                                showAccessible: function() {
                                    this.removeClass(CSS_BOOTSTRAP_SR_ONLY);
                                },
                            
                                /**
                                 * Toggles the node visibility, while still keeping it accessible by screen\
                                 * readers.
                                 *
                                 * @param {Boolean} force If true the node will be shown, otherwise it will
                                 *     be hidden.
                                 * @method toggleAccessible
                                 */
                                toggleAccessible: function(force) {
                                    force = (force !== undefined) ? force :
                                            this.hasClass(CSS_BOOTSTRAP_SR_ONLY);
                            
                                    if (force) {
                                        this.showAccessible();
                                    } else {
                                        this.hideAccessible();
                                    }
                                }
                            });