assertNotNull(hmac);
    }

    @Test
    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);

            lock = new Smb2Lock(100L, 200L, sharedWithFailImmediately);
            lock.encode(buffer, 0);

            assertEquals(0x11, SMBUtil.readInt4(buffer, 16));
        }
    }

    @Nested
    @DisplayName("Edge Cases and Boundary Tests")
    class EdgeCaseTests {

        @Test

                dst[dstIndex + 2 * i + 2] = (byte) ((tmp[i] & 0x0F) + 0x41);
            }
            for (; i < 15; i++) {
                dst[dstIndex + 2 * i + 1] = (byte) 0x43;
                dst[dstIndex + 2 * i + 2] = (byte) 0x41;
            }
            dst[dstIndex + TYPE_OFFSET] = (byte) (((hexCode & 0xF0) >> 4) + 0x41);

        byte[] server = hex("0102030405060708");
        byte[] client = hex("DEADBEEFCAFEBABE");

        // Act
        byte[] a = NtlmUtil.getNTLM2Response(pwdHash, server, client);
        server[7] ^= 0x01; // mutate
        byte[] b = NtlmUtil.getNTLM2Response(pwdHash, server, client);

        // Assert
        assertEquals(24, a.length);

    static final int FILE_SYNCHRONOUS_IO_ALERT = 0x00000010;
    static final int FILE_SYNCHRONOUS_IO_NONALERT = 0x00000020;

    // security flags
    static final int SECURITY_CONTEXT_TRACKING = 0x01;
    static final int SECURITY_EFFECTIVE_ONLY = 0x02;

    private int rootDirectoryFid;

    private final int extFileAttributes;

    private final int shareAccess;

    private int createDisposition;

        when(this.mechContext.getFlags()).thenReturn(0x1234);
        when(this.mechContext.initSecContext(any(byte[].class), eq(0), eq(0))).thenReturn(new byte[] { 0x01, 0x02 });

        // Act: len==0 triggers initial token construction
        byte[] out = ctx.initSecContext(null, 0, 0);

        // Assert: returns a SPNEGO token (opaque here but non-null/non-empty)

            byte[] buffer1 = new byte[100];
            byte[] buffer2 = new byte[200];

            Arrays.fill(buffer1, (byte) 0x11);
            Arrays.fill(buffer2, (byte) 0x22);

            // First decode
            response.decode(buffer1, 0, 50);
            byte[] data1 = response.getData();

        // Random but realistic GUID
        byte[] testGuid = { (byte) 0x01, (byte) 0x23, (byte) 0x45, (byte) 0x67, (byte) 0x89, (byte) 0xAB, (byte) 0xCD, (byte) 0xEF,
                (byte) 0xFE, (byte) 0xDC, (byte) 0xBA, (byte) 0x98, (byte) 0x76, (byte) 0x54, (byte) 0x32, (byte) 0x10 };

        // Security mode with signing required

        byte[] nb = name.getBytes();
        int len = 2 + 2 + der.length + 4 + nb.length;
        byte[] out = new byte[len];
        int i = 0;
        out[i++] = 0x04; // TOK_ID[0]
        out[i++] = 0x01; // TOK_ID[1]
        out[i++] = (byte) ((der.length >> 8) & 0xFF);
        out[i++] = (byte) (der.length & 0xFF);
        System.arraycopy(der, 0, out, i, der.length);
        i += der.length;

	o = msgp.AppendString(o, z.ID)
	// string "User"
	o = append(o, 0xa4, 0x55, 0x73, 0x65, 0x72)
	o = msgp.AppendString(o, z.User)
	// string "Started"
	o = append(o, 0xa7, 0x53, 0x74, 0x61, 0x72, 0x74, 0x65, 0x64)
	o = msgp.AppendTime(o, z.Started)
	// string "Replicate"
	o = append(o, 0xa9, 0x52, 0x65, 0x70, 0x6c, 0x69, 0x63, 0x61, 0x74, 0x65)
	if z.Replicate == nil {
		o = msgp.AppendNil(o)
	} else {