[catnaroek]

So the behavior of a subclass of an abstract class depends on whether both classes are defined in the same module or in different ones:

(0) If Snake is in the same module as Animal, the error is that “john.pet.talk” is a call to a nonexistent method.

(1) If Snake is in a different module from Animal, the errors is that Snake doesn't have a talk method.

This isn't nice.