I was looking at twitters embed code and saw that they are using !function ... while i know that this evaluates to false I was wondering what the point of it was. thoughts? !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");