/**
   * Cached value of #publicSuffixIndex(). Do not use directly.
   *
   * <p>Since this field isn't {@code volatile}, if an instance of this class is shared across
   * threads before it is initialized, then each thread is likely to compute their own copy of the
   * value.
   */
  @SuppressWarnings("Immutable")
  @LazyInit
  private int publicSuffixIndexCache = SUFFIX_NOT_INITIALIZED;

  /**

 *  New: Share threads more aggressively between OkHttp's HTTP/2 connections, connection pool,
    web sockets, and cache. OkHttp has a new internal task runner abstraction for managed task
    scheduling. In your debugger you will see new thread names and more use of daemon threads.

 *  Fix: Don't drop callbacks on unexpected exceptions. When an interceptor throws an unchecked

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible

        this.localInterfaces = new ArrayList<>();
        this.remoteInterfaces = new ArrayList<>();
        this.scheduler = Executors.newScheduledThreadPool(2, r -> {
            Thread t = new Thread(r, "MultiChannelScheduler");
            t.setDaemon(true);
            return t;
        });
        this.loadBalancer = new ChannelLoadBalancer(this);
        this.failover = new ChannelFailover(this);

 * useForNull} has no effect on the instance it is invoked on! You must store and use the new joiner
 * instance returned by the method. This makes joiners thread-safe, and safe to store as {@code
 * static final} constants.
 *
 * {@snippet :
 * // Bad! Do not do this!
 * Joiner joiner = Joiner.on(',');
 * joiner.skipNulls(); // does nothing!

import (
	"sync"
	"time"
)

// EvictCallback is used to get a callback when a cache entry is evicted
type EvictCallback[K comparable, V any] func(key K, value V)

// LRU implements a thread-safe LRU with expirable entries.
type LRU[K comparable, V any] struct {
	size      int
	evictList *LruList[K, V]
	items     map[K]*Entry[K, V]
	onEvict   EvictCallback[K, V]

	// expirable options
	mu   sync.Mutex

- **Logging Abstraction** (`org.codelibs.core.log`) - Flexible logging system supporting JCL (Jakarta Commons Logging) and JUL (Java Util Logging)
- **Concurrent Utilities** (`org.codelibs.core.concurrent`) - Thread-safe collections and concurrency helpers using modern concurrent APIs
- **Crypto & Security** (`org.codelibs.core.crypto`, `org.codelibs.core.security`) - Basic cryptographic utilities, message digest operations, and secure random generation

                    }
                });
            }

            executor.shutdown();
            assertTrue(executor.awaitTermination(30, TimeUnit.SECONDS), "All threads should complete within timeout");

            // Analyze timing consistency across threads
            if (!timings.isEmpty()) {
                double avgTime = timings.stream().mapToLong(Long::longValue).average().orElse(0.0);

  }

  /**
   * Creates a thread-safe set backed by a hash map. The set is backed by a {@link
   * ConcurrentHashMap} instance, and thus carries the same concurrency guarantees.
   *
   * <p>Unlike {@code HashSet}, this class does NOT allow {@code null} to be used as an element. The
   * set is serializable.
   *
   * @return a new, empty thread-safe {@code Set}
   * @since 15.0
   */