Homebrew install specific version of a binary

When you, like me, jump on new update ... let's say play framework 2.2.1 and you don't check your dependencies are ready to take the jump too, or you're working on a environment which not ready to jump on a new version, how to downgrade to a previous version of a binary ?

Brew let us doing this in a super easy way. In fact brew let you have multiple version of the same binary installed on your computer and let you switch from a version to another with the switch command :

brew switch play 2.2.0

Easy isn't it ? it just change the simlink so it's blazing fast.