HMACT64 hmac = new HMACT64(TEST_KEY);
        hmac.engineUpdate(TEST_DATA, 0, TEST_DATA.length);
        // No exception means success
    }

    @Test
    void testEngineUpdateByteArrayPartial() {
        // Test engineUpdate with partial array
        HMACT64 hmac = new HMACT64(TEST_KEY);
        hmac.engineUpdate(TEST_DATA, 2, TEST_DATA.length - 2);
        // No exception means success
    }