}
        } else {
          // In the case of a concurrent remove, we might observe a zero value, which means another
          // thread is about to remove (element, existingCounter) from the map. Rather than wait,
          // we can just do that work here.
          AtomicInteger newCounter = new AtomicInteger(occurrences);

  private OverflowAvoidingLockSupport() {}

  static void parkNanos(@Nullable Object blocker, long nanos) {
    // Even in the extremely unlikely event that a thread unblocks itself early after only 68 years,
    // this is indistinguishable from a spurious wakeup, which LockSupport allows.
    LockSupport.parkNanos(blocker, min(nanos, MAX_NANOSECONDS_THRESHOLD));
  }

     * -2: use system default, -1: never expire, 0 or positive: expire after specified days.
     */
    protected int documentExpires = -2;

    /**
     * Hot thread monitoring interval in seconds.
     * -1: disabled, positive value: enable hot thread monitoring with specified interval.
     * Used for performance analysis and debugging of the crawler process.
     */
    protected int hotThreadInterval = -1;

    /**

 * violate the {@code Set} contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
/*

   * and returns that value on subsequent calls to {@code get()}. See: <a
   * href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at
   * most once unless the underlying {@code get()} throws an exception. The supplier's serialized

 * not consistent with {@code equals}.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible

import java.lang.ref.PhantomReference;
import java.lang.ref.ReferenceQueue;
import org.jspecify.annotations.Nullable;

/**
 * Phantom reference with a {@code finalizeReferent()} method which a background thread invokes
 * after the garbage collector reclaims the referent. This is a simpler alternative to using a
 * {@link ReferenceQueue}.
 *
 * <p>Unlike a normal phantom reference, this reference will be cleared automatically.
 *

import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

 *   <li>Handle project forking states</li>
 * </ul>
 *
 * The service maintains the mutable state of projects as they progress through
 * their build lifecycle, ensuring thread-safety and proper state management.
 * All implementations must be thread-safe as they may be accessed concurrently
 * during parallel builds.
 *
 * @since 4.0.0
 * @see org.apache.maven.api.services.ProjectBuilder
 * @see Project
 */
@Experimental