`issubclass(1, list)` raises an Exception, complaining that `1` is not a
class. This is wrong in my opinion. It should just return False.
Use case: I have an object which can be either a list, or a string, or a
callable, or a type. And I want to check whether it's a sub-class of some
So I don't think I should be taking extra precautions before using
`issubclass`: If my object is not a subclass of the given base class, I
should just get `False`.