/**
 * 是否为有效的md5格式(32位)
 *
 * @param {string} val
 * @returns {boolean}
 * @example
 *
 * isValidMD5('21fe181c5bfc16306a6828c1f7b762e8');
 * // => true
 */
export declare function isValidMD5(val: string): boolean;