def METHOD_NAME(self, backend):
    cipher = Cipher(
        algorithms.AES(binascii.unhexlify(b"0" * 32)), modes.ECB(), backend
    )
    encryptor = cipher.encryptor()
    ct = encryptor.update(b"a" * 15)
    assert ct == b""
    ct += encryptor.update(b"a" * 65)
    assert len(ct) == 80
    ct += encryptor.finalize()
    decryptor = cipher.decryptor()
    pt = decryptor.update(ct[:3])
    assert pt == b""
    pt += decryptor.update(ct[3:])
    assert len(pt) == 80
    assert pt == b"a" * 80
    decryptor.finalize()