function base64EncodeUnicode(str) {
    // First we escape the string using encodeURIComponent to get the UTF-8 encoding of the characters, 
    // then we convert the percent encodings into raw bytes, and finally feed it to btoa() function.
    utf8Bytes = encodeURIComponent(str).replace(/%([0-9A-F]{2})/g, function(match, p1) {
            return String.fromCharCode('0x' + p1);
    });

    return btoa(utf8Bytes);
}

x.decode('utf-8').encode('raw_unicode_escape').decode('ascii')[2:].strip('0')