Request originated via reddit thread.

As of today, there is no mechanism to define all possible "valid" states of an object that uses decorstate transitions. An initial but not complete list of items to consider around this are:

• @machine class decorator, base class, or meta-class that allows more control of actual instance?
• How can we wrap the state attribute we set on the instance to validate/raise when someone explicitly sets the value to something that isn't defined?
• How does class state work on a descriptor object w.r.t multiple different classes using the descriptor? I believe I know the answer to this but a refresher on the underlying rules should help solidify the design.