def test_valid_assignment_upwards(self):
        D, B = self.classes.D, self.classes.B

        sess = Session()
        b1 = B()
        b1.class_name = 'd'
        sess.add(b1)
        sess.commit()
        sess.close()
        assert isinstance(sess.query(B).first(), D)
test that we can assign 'd' to a B, since B/D
dataset/ETHPy150Open zzzeek/sqlalchemy/test/orm/inheritance/test_basic.py/PolymorphicAttributeManagementTest.test_valid_assignment_upwards