class SomeTest(ORMTest):

    def define_tables(self, metadata):
        users = Table('users', metadata, ...)
        addresses = Table('addresses', metadata, ...)
        return dict(users=users, addresses=addresses)

    def define_classes(self):
        class User(object):
            pass
        class Address(object):
            pass

        return dict(User=User, Address=Address)

    def test_1(self):
        User, users = self.get_all('User', 'users')

        mapper(User, users)
        # ...

    def test_2(self):
        Address, addresses, User = self.get_all(
            'Address', 'addresses', 'User')

        mapper(Address, addresses, properties={
                'user': relation(User)
                })
        # ...