?? 'foo', 'asdf2345':
>> OK AGZvbwBhc2RmMjM0NQ== = AGZvbwBhc2RmMjM0NQ==

?? 'foo', '':
>> OK AGZvbwA= = AGZvbwA=

?? '', 'asdf2345':
>> OK AABhc2RmMjM0NQ== = AABhc2RmMjM0NQ==

?? '', '':
>> OK AAA= = AAA=

