def METHOD_NAME(self, backend):
    cipher = Cipher(
        algorithms.AES(b"\x00" * 16), modes.CBC(b"\x00" * 16), backend
    )
    encryptor = cipher.encryptor()
    encryptor.update(b"1")
    with pytest.raises(ValueError):
        encryptor.finalize()
    decryptor = cipher.decryptor()
    decryptor.update(b"1")
    with pytest.raises(ValueError):
        decryptor.finalize()