@Override
    public String toSpec() {
        return String.format("plain:%s:%s", algorithm.toString().toLowerCase(), Base64.getEncoder().encodeToString(plainKey));
    }
@Test
    public void testToSpec() {
        String base64Key = Base64.getEncoder().encodeToString(normalKey.getPlainKey());
        String expectedSpec = "plain:aes_128:" + base64Key;
        assertEquals(expectedSpec, normalKey.toSpec());
    }