SecretKeySpec key = new SecretKeySpec(new byte[16], "ARCFOUR");
        byte[] mac = PacMac.calculateMacArcfourHMACMD5(3, key, TEST_DATA);
        assertNotNull(mac);
        assertEquals(16, mac.length);

        // Test with a different key usage
        byte[] mac2 = PacMac.calculateMacArcfourHMACMD5(9, key, TEST_DATA);
        assertNotNull(mac2);
        assertEquals(16, mac2.length);

        // Test with another key usage

        SMBUtil.writeInt4(TRANSFORM_PROTOCOL_ID, dst, dstIndex);
        dstIndex += 4;

        // Signature (16 bytes)
        System.arraycopy(this.signature, 0, dst, dstIndex, 16);
        dstIndex += 16;

        // Nonce (16 bytes)
        System.arraycopy(this.nonce, 0, dst, dstIndex, 16);
        dstIndex += 16;

        // Original message size
        SMBUtil.writeInt4(this.originalMessageSize, dst, dstIndex);

        mockConfig = mock(Configuration.class);
        mockContext = mock(CIFSContext.class);
        when(mockContext.getConfig()).thenReturn(mockConfig);

        // Create a test file ID (16 bytes)
        testFileId = new byte[16];
        for (int i = 0; i < 16; i++) {
            testFileId[i] = (byte) (i + 1);
        }

        testFileName = "test-file.txt";
        request = new Smb2CloseRequest(mockConfig, testFileId, testFileName);

    assertThat(rangeSet.complement().asRanges())
        .containsExactly(Range.lessThan(1), Range.greaterThan(6))
        .inOrder();
  }

  public void testIgnoresEqual() {
    TreeRangeSet<Integer> rangeSet = TreeRangeSet.create();
    rangeSet.add(Range.closed(1, 6));
    rangeSet.add(Range.closed(1, 6));
    testInvariants(rangeSet);
    assertThat(rangeSet.asRanges()).contains(Range.closed(1, 6));

            assertEquals(16, derivedKey.length, "Should always produce 16-byte key regardless of input size");
        }
    }

    @Test
    @DisplayName("Should derive unique keys for different session keys")
    void testDeriveKeys_UniqueSessionKeys() {
        // Given
        byte[] sessionKey1 = new byte[16];
        byte[] sessionKey2 = new byte[16];
        new SecureRandom().nextBytes(sessionKey1);

        // The decode method returns only the header size (16 bytes)\n        assertEquals(16, bytesDecoded);
    }

    @Test
    @DisplayName("Test decode without data")
    void testDecodeWithoutData() throws SMBProtocolDecodingException {
        // Prepare test data - only header, no data
        byte[] buffer = new byte[16];
        int bufferIndex = 0;

        // Set up test values

    private static final int STRUCTURE_SIZE = 16;

    private byte[] fileId; // 16-byte file ID from previous open

    /**
     * Create a new durable handle reconnect context
     * @param fileId the 16-byte file ID from the previous open
     */
    public DurableHandleReconnect(byte[] fileId) {
        if (fileId.length != 16) {
            throw new IllegalArgumentException("File ID must be 16 bytes");
        }

     *
     * @param key 16-byte array
     * @throws IllegalArgumentException if key is not 16 bytes
     */
    public Smb2LeaseKey(byte[] key) {
        if (key == null) {
            throw new IllegalArgumentException("Lease key cannot be null");
        }
        if (key.length != LEASE_KEY_SIZE) {
            throw new IllegalArgumentException("Lease key must be 16 bytes, got " + key.length);
        }

            SMBUtil.writeInt4(50, minBuffer, 8);
            SMBUtil.writeInt4(0, minBuffer, 12);
            SMBUtil.writeInt4(0, minBuffer, 16);

            int bytesRead = response.readBytesWireFormat(minBuffer, 0);
            assertEquals(16, bytesRead);
            assertEquals(100, response.getCount());
            assertEquals(50, response.getRemaining());

            // Large buffer

	}

	// write 4 * 4 = 16 bytes
	n, err := rb.Write([]byte(strings.Repeat("abcd", 4)))
	if err != nil {
		t.Fatalf("write failed: %v", err)
	}
	if n != 16 {
		t.Fatalf("expect write 16 bytes but got %d", n)
	}
	if rb.Length() != 16 {
		t.Fatalf("expect len 16 bytes but got %d. r.w=%d, r.r=%d", rb.Length(), rb.w, rb.r)
	}
	if rb.Free() != 48 {
		t.Fatalf("expect free 48 bytes but got %d. r.w=%d, r.r=%d", rb.Free(), rb.w, rb.r)