Where can I find the latest /jsbin/www-widgetapi file?

Where can I find the latest /jsbin/www-widgetapi file?

I'm currently loading the YouTube API like so:
$(function () {
// This code will trigger onYouTubePlayerAPIReady
$('<script>', {
src: 'https://s.ytimg.com/yts/jsbin/www-widgetapi-vflwt8QCF.js',
async: true
}).insertBefore($('script:first'));
});
I was looking at the YouTube demo page,
https://developers.google.com/youtube/youtube_player_demo, and I noticed
in their source that they were using a different URL to load their widget
API:
<script src="https://s.ytimg.com/yts/jsbin/www-widgetapi-vfl4qCmf3.js"
async></script>
I thought that this might be a more up-to-date version of their API. So, I
swapped it out, but I receive an error message:
Uncaught ReferenceError: YTConfig is not defined
I'm left wondering which of these is the correct location, if either, to
be loading the most up to date widgetapi data from. Is there a location
for this info?