`NEXT.pm`

        $self->SUPER::DESTROY;

But what if $self has more than one base class?
- Which DESTROY method is called?
- Only the first one, it turns out.

Suppose each DESTROY calls SUPER::DESTROY
- Unfortunately, that's not enough
- D::DESTROY calls B::DESTROY
- B::DESTROY calls A::DESTROY
- C::DESTROY is never called