def test_with_managers_delete(self):
        m = mock.Mock()
        m.delete.return_value = True

        manager = ChainManager([("fs", m)])

        self.assertTrue(manager.delete("hello"))
    def test_with_no_manager(self):
        manager = ChainManager(None)

        with self.assertRaises(Exception):
            manager.retrieve("none")

        self.assertFalse(manager.exists("id"))
        self.assertFalse(manager.delete("id"))