/**
 * A {@link Specification} that passes when a data item is an undefined value.
 *
 * @public
 * @extends {Specification}
 */
export default class Undefined extends Specification {
    /**
     * @protected
     * @override
     * @param {*} data
     * @returns {boolean}
     */
    protected override _evaluate(data: any): boolean;
}
import Specification from './Specification.js';