// Test with URL, message, exception, and abort set to true
        String url = "http://example.com/test2";
        String message = "Critical error message";
        Exception cause = new IllegalStateException("Critical error");
        boolean abort = true;

        DataStoreCrawlingException exception = new DataStoreCrawlingException(url, message, cause, abort);

/**
 * System exception class for the Fess search engine.
 * This exception is thrown when system-level errors occur in the Fess application,
 * such as configuration errors, initialization failures, or critical runtime issues.
 */
public class FessSystemException extends RuntimeException {

    /** Serial version UID for serialization compatibility */
    private static final long serialVersionUID = 1L;

    /**

/**
 * Log4j rewrite policy that converts ERROR level log events to WARN level for specified loggers.
 * This policy is useful for downgrading the severity of log events from certain loggers
 * to prevent them from being treated as critical errors.
 */
@Plugin(name = "ErrorToWarnRewritePolicy", category = Core.CATEGORY_NAME, elementType = "rewritePolicy", printObject = true)
public class ErrorToWarnRewritePolicy implements RewritePolicy {

      }
    }
    return added;
  }

  /**
   * Returns a synchronized (thread-safe) queue backed by the specified queue. In order to guarantee
   * serial access, it is critical that <b>all</b> access to the backing queue is accomplished
   * through the returned queue.
   *
   * <p>It is imperative that the user manually synchronize on the returned queue when accessing the
   * queue's iterator:

      }
    }
    return added;
  }

  /**
   * Returns a synchronized (thread-safe) queue backed by the specified queue. In order to guarantee
   * serial access, it is critical that <b>all</b> access to the backing queue is accomplished
   * through the returned queue.
   *
   * <p>It is imperative that the user manually synchronize on the returned queue when accessing the
   * queue's iterator:

        }
        i++;
      }
      return true;
    }

    @Override
    public boolean equals(@Nullable Object object) {
      // Warning: this is broken if size() == 0, so it is critical that we
      // substitute an empty ImmutableSet to the user in place of this
      if (object instanceof CartesianSet) {
        CartesianSet<?> that = (CartesianSet<?>) object;

  }

  /**
   * Returns a synchronized (thread-safe) table backed by the specified table. In order to guarantee
   * serial access, it is critical that <b>all</b> access to the backing table is accomplished
   * through the returned table.
   *
   * <p>It is imperative that the user manually synchronize on the returned table when accessing any

    MinMaxPriorityQueue<Integer> q = MinMaxPriorityQueue.create(initial);
    assertIntact(q);
    q.remove(9);
    q.remove(11);
    q.remove(10);
    // Now we're in the critical state: [1, 15, 13, 8, 14]
    // Removing 8 while iterating caused duplicates in iteration result.
    List<Integer> result = Lists.newArrayListWithCapacity(initial.size());

_2023-12-17_

We took too long to cut this release and there's a lot of changes in it. We've been busy.

Although this release is labeled _alpha_, the only unstable thing in it is our new APIs. This
release has many critical bug fixes and is safe to run in production. We're eager to stabilize our
new APIs so we can get out of alpha.

 *  New: Support Java 21's virtual threads (‘OpenJDK Project Loom’). We changed OkHttp's internals

 *         <li>20 levels: average of 393ns per lock()/unlock()
 *       </ul>
 * </ul>
 *
 * <p>As such, the CycleDetectingLockFactory may not be suitable for performance-critical
 * applications which involve tightly-looped or deeply-nested locking algorithms.
 *
 * @author Darick Tong
 * @since 13.0
 */
@J2ktIncompatible
@GwtIncompatible
public class CycleDetectingLockFactory {