When programming Tk, it's almost always a good idea to keep a reference to the
widgets that you created in the interface. Most of the time, a simple hash is
enough; but it is usually wrapped up in methods to make the hash private to the
window object. And of course, those methods are duplicated in all modules, under
a form or another.

Since duplication is bad, this module implements a Moose role implementing those
methods once and forever. This implies that your class is using Moose in order
to consume the role.