ault 'name'
         */
        valueattr: 'name',

        /**
         * Specifies the CSS class to be used to add to the selected element.
         *
         * @attribute selectedClass
         * @type string
         * @default 'core-selected'
         */
        selectedClass: 'core-selected',

        /**
         * Specifies the property to be used to set on the selected element
         * to indicate its active state.
         *
         * @attribute selectedProperty
         * @type string
       