protected String preferredCiphers = "AES_128_GCM,AES_128_CCM,AES_256_GCM,AES_256_CCM";
    /** Whether AES-256 encryption is enabled */
    protected boolean aes256Enabled = true;
    /** Whether to use SMB2/SMB3 leases for caching */
    protected boolean useLease = true;
    /** Lease timeout in milliseconds */
    protected int leaseTimeout = 30000;
    /** Maximum number of concurrent leases */
    protected int maxLeases = 1000;

import java.util.HashMap;
import java.util.Iterator;

import jcifs.smb1.Config;
import jcifs.smb1.UniAddress;
import jcifs.smb1.util.LogStream;

/**
 * Implements DFS (Distributed File System) referral caching and resolution.
 * This class manages DFS referral cache and provides DFS path resolution functionality.
 */
public class Dfs {

    /**
     * Default constructor for Dfs.
     * Initializes the DFS referral system.

    fun isCacheable(
      response: Response,
      request: Request,
    ): Boolean {
      // Always go to network for uncacheable response codes (RFC 7231 section 6.1), This
      // implementation doesn't support caching partial content.
      when (response.code) {
        HTTP_OK,
        HTTP_NOT_AUTHORITATIVE,
        HTTP_NO_CONTENT,
        HTTP_MULT_CHOICE,
        HTTP_MOVED_PERM,
        HTTP_NOT_FOUND,

                /*
                 * The SMB_COM_NT_CREATE_ANDX response wordCount is wrong. There's an
                 * extra 16 bytes for some "Offline Files (CSC or Client Side Caching)"
                 * junk. We need to bump up the wordCount here so that this method returns
                 * the correct number of bytes for signing purposes. Otherwise we get a
                 * signing verification failure.

    /*
     * This test will catch problems where the underlying iterator
     * throws a RuntimeException when retrieving the nth element.
     *
     * If the PeekingIterator is caching elements too aggressively,
     * it may throw the exception on the (n-1)th element (oops!).
     */

    /* Checks the case where the first element throws an exception. */

    List<Integer> list = emptyList();

    builder.build(CacheLoader.from(Suppliers.ofInstance(null)));
  }

  public void testDisableCaching() {
    // Functional test: assert that CacheBuilderSpec.disableCaching()
    // disables caching.  It's irrelevant how it does so.
    CacheBuilder<Object, Object> builder = CacheBuilder.from(CacheBuilderSpec.disableCaching());
    Object key = new Object();
    Object value = new Object();

### Performance Optimizations
- **Caching** - Bean descriptors and reflection metadata are cached for improved performance
- **Lazy initialization** - Resources and expensive operations are initialized only when needed  
- **Memory efficient** - Specialized collections like `LruHashMap` and `ArrayMap` for memory-conscious applications
- **Java 21 features** - Switch expressions and pattern matching for reduced overhead

```java
/** Dangerous interceptor that rewrites the server's cache-control header. */
private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() {

  }

  /**
   * Provides a check of whether an exception type is valid for use with {@link
   * FuturesGetChecked#getChecked(Future, Class)}, possibly using caching.
   *
   * <p>Uses reflection to gracefully fall back to when certain implementations aren't available.
   */
  private static final class GetCheckedTypeValidatorHolder {

    closing the input stream and output stream of a socket is not sufficient.
 *  Fix: Buffer outgoing HTTP/2 frames to limit how many outgoing frames are
    created.
 *  Fix: Avoid crashing when cache writing fails due to a full disk.
 *  Fix: Improve caching of private responses.
 *  Fix: Update cache-by-default response codes.
 *  Fix: Reused `Request.Builder` instances no longer hold stale URL fields.