*/

package com.google.common.util.concurrent;

import static com.google.common.base.StandardSystemProperty.JAVA_SPECIFICATION_VERSION;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.collect.ImmutableSet;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.URLClassLoader;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;

 * the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.errorprone.annotations.concurrent.GuardedBy;
import java.util.concurrent.Executor;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

        // Use reflection to access concurrent collections
        Field connectionsField = SmbTransportPoolImpl.class.getDeclaredField("connections");
        connectionsField.setAccessible(true);
        @SuppressWarnings("unchecked")
        java.util.concurrent.ConcurrentLinkedQueue<SmbTransportImpl> connections =
                (java.util.concurrent.ConcurrentLinkedQueue<SmbTransportImpl>) connectionsField.get(pool);

import java.nio.charset.UnsupportedCharsetException;
import java.util.ConcurrentModificationException;
import java.util.NoSuchElementException;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

import java.nio.charset.UnsupportedCharsetException;
import java.util.ConcurrentModificationException;
import java.util.NoSuchElementException;
import java.util.concurrent.CancellationException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeoutException;
import junit.framework.AssertionFailedError;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

        }
    }
}
```

### 4.3 Directory Lease Manager
```java
package jcifs.internal.smb2.lease;

import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class DirectoryLeaseManager {
    private final CIFSContext context;

import java.io.IOException;
import java.io.InputStream;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Test class for SMB file locking operations.
 * This class is used to test concurrent file access and locking behavior.
 */
public class TestLocking implements Runnable {

    private static final Logger logger = LoggerFactory.getLogger(TestLocking.class);

    /**

 * the License.
 */

package com.google.common.util.concurrent;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.concurrent.Callable;
import org.jspecify.annotations.Nullable;

/**

import java.net.InetAddress;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jcifs.CIFSContext;

 */

package com.google.common.util.concurrent;

import static com.google.common.truth.Truth.assertThat;
import static java.util.concurrent.Executors.defaultThreadFactory;
import static org.junit.Assert.assertThrows;

import com.google.common.testing.NullPointerTester;
import java.lang.Thread.UncaughtExceptionHandler;
import java.util.Locale;
import java.util.concurrent.ThreadFactory;
import junit.framework.TestCase;