Given how this module is mixed-in, methods here become methods in the scope of the user's specs.  They don't need this method, and if they were to define their own method named this, it would cause problems.

It looks like this acts only on the given args, so can this be turned into a class method, and then you can use `Pending.set_message!` to call it?

Also, since this is an easy mistake to make, it would be good to add a spec that fails if someone accidentally adds a helper method like this -- basically it could assert that the instance methods of the module contain only a known whitelist of allowed methods (e.g. `pending` and `skip`).