import java.nio.ByteBuffer;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.atomic.AtomicInteger;

public abstract class RdmaConnection implements AutoCloseable {
    protected final InetSocketAddress remoteAddress;
    protected final InetSocketAddress localAddress;
    protected final AtomicInteger sendCredits;
    protected final AtomicInteger receiveCredits;

 */

/**
 * Abstract base class for network transport implementations in JCIFS.
 * This class handles the low-level transport protocol for SMB communication.
 */
public abstract class Transport implements Runnable, AutoCloseable {

    /**
     * Default constructor for Transport
     */
    protected Transport() {
        // Default constructor
    }

    private static int id = 0;

 * - Uses PBKDF2 for key derivation from master password
 * - Secure wiping of sensitive data
 * - Thread-safe operations
 * - Protection against timing attacks
 */
public class SecureCredentialStorage implements AutoCloseable, Destroyable {

    private static final Logger log = LoggerFactory.getLogger(SecureCredentialStorage.class);

    private static final String ENCRYPTION_ALGORITHM = "AES/GCM/NoPadding";

 * - Global rate limiting
 * - Exponential backoff for repeated failures
 * - Account lockout after threshold
 * - Automatic cleanup of old entries
 */
public class AuthenticationRateLimiter implements AutoCloseable {

    private static final Logger log = LoggerFactory.getLogger(AuthenticationRateLimiter.class);

    // Rate limiting configuration
    private final int maxAttemptsPerAccount;

    private LeaseManager baseLeaseManager;

    @Mock
    private SmbFile mockFile1;

    @Mock
    private SmbFile mockFile2;

    private DirectoryLeaseManager directoryLeaseManager;
    private AutoCloseable mocks;

    @BeforeEach
    public void setUp() {
        mocks = MockitoAnnotations.openMocks(this);
        when(context.getConfig()).thenReturn(config);

```

### 4.3 Witness Client
```java
package jcifs.internal.witness;

import jcifs.dcerpc.*;
import jcifs.dcerpc.rpc.*;
import java.util.concurrent.*;

public class WitnessClient implements AutoCloseable {
    private final InetAddress witnessServer;
    private final int port;
    private final CIFSContext context;
    private final ConcurrentHashMap<String, WitnessRegistration> registrations;

 * message integrity and authenticity. It supports different signing algorithms
 * used in various SMB2/SMB3 dialect versions.
 *
 * @author mbechler
 */
public class Smb2SigningDigest implements SMBSigningDigest, AutoCloseable {

    private static final Logger log = LoggerFactory.getLogger(Smb2SigningDigest.class);

    /**
     *
     */
    private static final int SIGNATURE_OFFSET = 48;

/**
 * SMB Witness Protocol client implementation as defined in MS-SWN specification.
 * Manages witness registrations, notifications, and heartbeats for cluster failover support.
 */
public class WitnessClient implements AutoCloseable {
    private static final Logger log = LoggerFactory.getLogger(WitnessClient.class);

    // Polling and backoff constants (in ms)
    private static final long MAX_POLL_INTERVAL = 5000; // Normal polling: max 5 seconds

            watchHandle.close();
        });

        assertEquals("Failed to close handle", thrown.getMessage());
        verify(watchHandle, times(1)).close();
    }

    /**
     * Test AutoCloseable behavior with try-with-resources
     */
    @Test
    void testAutoCloseable() throws CIFSException {
        // Create a mock that tracks close calls

/**
 * Abstract base class for DCE/RPC communication handles.
 * This class provides the foundation for DCE/RPC client communication.
 */
public abstract class DcerpcHandle implements DcerpcConstants, AutoCloseable {

    /*
     * Bindings are in the form:
     * proto:\\server[key1=val1,key2=val2]
     * or
     * proto:server[key1=val1,key2=val2]
     * or
     * proto:[key1=val1,key2=val2]
     *