# Add Behaviors to Objects with `mix`

Static classes in JavaScript are implemented as object literals with keys corresponding to public class methods. As such, static classes aren't candidates for instantiation or prototype extention. To add functionality to static classes, you need to work with the class's object literal & and that's what YUI's `mix` method helps you to do.

Click the button below to call methods `mix`ed into a static class, then read the tutorial below for more information about using `mix`.