RotMG Editor and Private Server

I've heard that you can test your maps when you run somekind of local private server. Anyone knows more about this?

Also if someone could make video tutorial about it, I would really appreciate it.

At least Mitcheel said here that it works: http://www.mpgh.net/forum/655-realm-...ap-editor.html
But how? Do I need to make Editor Client to connect to my server? If yes how to change where it connect?