/**
 * 是否为有效的IP v6
 *
 * @param {string} val
 * @returns {boolean}
 * @example
 *
 * isValidIPV6('2031:0000:130f:0000:0000:09c0:876a:130b');
 * // => true
 *
 */
export declare function isValidIPV6(val: string): boolean;