void testEngineUpdateByte() {
        // Test engineUpdate(byte b)
        HMACT64 hmac = new HMACT64(TEST_KEY);
        hmac.engineUpdate((byte) 0x01);
        // No exception means success
    }

    @Test
    void testEngineUpdateByteArray() {
        // Test engineUpdate(byte[] input, int offset, int len)
        HMACT64 hmac = new HMACT64(TEST_KEY);
        hmac.engineUpdate(TEST_DATA, 0, TEST_DATA.length);

    }

    @Test
    void testEngineUpdateByte() throws NoSuchAlgorithmException {
        // Test engineUpdate(byte b)
        try (MockedStatic<Crypto> mockedCrypto = mockStatic(Crypto.class)) {
            mockedCrypto.when(Crypto::getMD5).thenReturn(mockMd5);
            HMACT64 hmac = new HMACT64(TEST_KEY);
            hmac.engineUpdate((byte) 0x01);
            verify(mockMd5, times(1)).update((byte) 0x01);
        }
    }

    protected void engineReset() {
        this.md5.reset();
        this.md5.update(this.ipad);
    }

    @Override
    protected void engineUpdate(final byte b) {
        this.md5.update(b);
    }

    @Override
    protected void engineUpdate(final byte[] input, final int offset, final int len) {
        this.md5.update(input, offset, len);
    }

    @Override
    protected void engineReset() {
        md5.reset();
        md5.update(ipad);
    }

    @Override
    protected void engineUpdate(final byte b) {
        md5.update(b);
    }

    @Override
    protected void engineUpdate(final byte[] input, final int offset, final int len) {
        md5.update(input, offset, len);
    }

            buffer[i] = 0;
        }
    }

    /**
     * Continues an MD4 message digest using the input byte.
     */
    @Override
    public void engineUpdate(final byte b) {
        // compute number of bytes still unhashed; ie. present in buffer
        final int i = (int) (count % BLOCK_LENGTH);
        count++; // update number of bytes
        buffer[i] = b;