/**
 * base64编码和解码
 * @param str
 * @returns
 */
declare const base64: {
    _keyStr: string;
    encode: (e: string) => string;
    decode: (e: string) => string;
    _utf8_encode: (e: string) => string;
    _utf8_decode: (e: string) => string;
};
export default base64;