import java.util.ArrayDeque;
import java.util.Deque;
import java.util.Iterator;
import java.util.Queue;
import org.jspecify.annotations.Nullable;

/**
 * Views elements of a type {@code T} as nodes in a tree, and provides methods to traverse the trees
 * induced by this traverser.
 *
 * <p>For example, the tree
 *
 * {@snippet :
 *        h
 *      / | \
 *     /  e  \
 *    d       g
 *   /|\      |
 *  / | \     f

/**
 * Helper class for managing content length limits based on MIME types.
 * It allows setting default and MIME type-specific maximum content lengths.
 * The class provides methods to add, retrieve, and manage these limits.
 */
public class ContentLengthHelper {
    /**
     * Constructs a new ContentLengthHelper.
     */
    public ContentLengthHelper() {
        // Default constructor

/**
 * Implementation of the {@link Authentication} interface.
 * This class provides methods to handle authentication details such as
 * authentication scope, credentials, and authentication scheme.
 *
 * <p>
 * It includes constructors to initialize these details and getter and setter
 * methods to access and modify them.
 * </p>
 *
 * <p>
 * Example usage:
 * </p>
 * <pre>
 * {@code

   * methods ensure that the {@code WrappedCollection} and map remain consistent.
   *
   * <p>A subcollection, such as a sublist, contains some of the values for a given key. Its
   * ancestor field points to the full wrapped collection with all values for the key. The
   * subcollection {@code refreshIfEmpty}, {@code removeIfEmpty}, and {@code addToMap} methods call

 *
 * <p>{@code CharSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a reader:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned reader is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are

 *
 * <p>{@code CharSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a reader:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned reader is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are

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

/**
 * An object with an operational state, plus asynchronous {@link #startAsync()} and {@link
 * #stopAsync()} lifecycle methods to transition between states. Example services include
 * webservers, RPC servers and timers.
 *
 * <p>The normal lifecycle of a service is:
 *
 * <ul>
 *   <li>{@linkplain State#NEW NEW} -&gt;

import org.codelibs.fess.crawler.log.LogType;

/**
 * Implementation of the {@link LogHelper} interface.
 * This class provides methods for logging various events during the crawling process.
 * It uses Log4j2 for logging.
 *
 * <p>
 * The class contains methods for logging different types of events, such as:
 * </p>
 * <ul>
 *   <li>Starting and finishing threads</li>
 *   <li>Starting and cleaning up crawling</li>

 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},
 *       typically because the type forbids nullable type arguments: For example, {@code

 *       String}.
 * </ul>
 *
 * This is the same behavior as type-variable usages have to Kotlin and to the Checker Framework.
 * Contrast the method above to:
 *
 * <ul>
 *   <li>methods whose return type is a type variable but which can never return {@code null},
 *       typically because the type forbids nullable type arguments: For example, {@code