// Given
        CommonServerMessageBlockRequest implementation = mock(CommonServerMessageBlockRequest.class);

        // When/Then - Verify the interface extends the expected interfaces
        assertTrue(CommonServerMessageBlock.class.isAssignableFrom(CommonServerMessageBlockRequest.class));
        assertTrue(jcifs.util.transport.Request.class.isAssignableFrom(CommonServerMessageBlockRequest.class));
    }

import org.junit.jupiter.api.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

/**
 * Test class for CommonServerMessageBlock interface
 */
class CommonServerMessageBlockTest {

    @Mock
    private CommonServerMessageBlock messageBlock;

    @Mock
    private CommonServerMessageBlockResponse response;

    @Mock
    private SMBSigningDigest digest;

    @BeforeEach

        // When
        response.exception(ex);

        // Then
        verify(response).exception(ex);
    }

    @Test
    @DisplayName("Test CommonServerMessageBlock inherited methods")
    void testCommonServerMessageBlockMethods() throws SMBProtocolDecodingException {
        // Test decode method
        byte[] buffer = new byte[512];
        int bufferIndex = 0;

    private Request<CommonServerMessageBlockResponse> request;

    @Mock
    private CommonServerMessageBlockResponse response;

    @Mock
    private CIFSContext context;

    @Mock
    private CommonServerMessageBlock disconnectRequest;

    @Mock
    private CommonServerMessageBlockRequest nextRequest;

    @BeforeEach
    void setUp() {
        // Reset mocks before each test

            byte[] data = new byte[128];
            Arrays.fill(data, (byte) 0x42);
            CommonServerMessageBlock request = mock(CommonServerMessageBlock.class);
            CommonServerMessageBlock response = mock(CommonServerMessageBlock.class);

            // Sign with first digest
            digest1.sign(data, 0, data.length, request, response);

 */
class SMBSigningDigestTest {

    @Mock
    private SMBSigningDigest signingDigest;

    @Mock
    private CommonServerMessageBlock request;

    @Mock
    private CommonServerMessageBlock response;

    @Mock
    private CommonServerMessageBlock message;

    private byte[] testData;

    @BeforeEach
    void setUp() {
        MockitoAnnotations.openMocks(this);

     *
     * @return list of pending operations
     */
    public List<CommonServerMessageBlock> getPendingOperations() {
        return pendingOperations;
    }

    /**
     * Add a pending operation
     *
     * @param operation operation to add
     */
    public void addPendingOperation(CommonServerMessageBlock operation) {
        pendingOperations.add(operation);
    }

    /**

        // Create a defensive copy to avoid ConcurrentModificationException
        List<CommonServerMessageBlock> operationsCopy = List.copyOf(pendingOps);

        // Clear the failed channel's pending operations first
        failedChannel.clearPendingOperations();

        // Redistribute to healthy channels
        for (CommonServerMessageBlock op : operationsCopy) {
            try {

     *
     * @see jcifs.internal.SMBSigningDigest#sign(byte[], int, int, jcifs.internal.CommonServerMessageBlock,
     *      jcifs.internal.CommonServerMessageBlock)
     */
    @Override
    public void sign(final byte[] data, final int offset, final int length, final CommonServerMessageBlock request,
            final CommonServerMessageBlock response) {
        // Validate input parameters
        if (data == null) {

     *
     * @see jcifs.internal.SMBSigningDigest#sign(byte[], int, int, jcifs.internal.CommonServerMessageBlock,
     *      jcifs.internal.CommonServerMessageBlock)
     */
    @Override
    public void sign(final byte[] data, final int offset, final int length, final CommonServerMessageBlock request,
            final CommonServerMessageBlock response) {
        if (log.isTraceEnabled()) {