def test_register_defect(self): class Dummy: def __init__(self): self.defects = [] obj = Dummy() defect = object() policy = email.policy.EmailPolicy() policy.register_defect(obj, defect) self.assertEqual(obj.defects, [defect]) defect2 = object() policy.register_defect(obj, defect2) self.assertEqual(obj.defects, [defect, defect2])