Is there any way to re-order project tabs? I think files are loaded into the environment in tab order - so if you try to use one class as another class’s prototype (by doing “Blah = class(SuperBlah)”, and “SuperBlah” is loaded after “Blah”, then it will be undefined.
To get around this I had to create another file so it was on the right of the base class, then copy-paste the code into the new class, and delete/rename everything 
