import abc


class ConcreteSuperclass(object):
    pass


class MinimalInterface(metaclass=abc.ABCMeta):

    @abc.abstractmethod
    def my_abstract_method(self):
        raise NotImplementedError()


class UnexceptionalConcrete(ConcreteSuperclass, MinimalInterface):

    def __init__(self):
        super().__init__()

    def my_my_abstract_method(self):
        return None


class ExceptionalConcrete(Exception, MinimalInterface):

    def __init__(self):
        super().__init__()

    def my_my_abstract_method(self):
        return None

my_exceptional_concrete = ExceptionalConcrete()
my_unexceptional_concrete = UnexceptionalConcrete()