return None.INSTANCE;
  }

  /**
   * Determines whether a character is whitespace according to the latest Unicode standard, as
   * illustrated <a
   * href="http://unicode.org/cldr/utility/list-unicodeset.jsp?a=%5Cp%7Bwhitespace%7D">here</a>.
   * This is not the same definition used by other Java APIs. (See a <a

import org.testcontainers.containers.wait.strategy.Wait;
import org.testcontainers.junit.jupiter.Container;
import org.testcontainers.junit.jupiter.Testcontainers;
import org.testcontainers.utility.MountableFile;

import jcifs.CIFSContext;
import jcifs.Configuration;
import jcifs.SmbConstants;
import jcifs.config.PropertyConfiguration;
import jcifs.context.BaseContext;
import jcifs.context.SingletonContext;

import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.SynchronousQueue;

/**
 * Utility class for collections.
 *
 * @author koichik
 */
public abstract class CollectionsUtil {

    /**
     * Do not instantiate.
     */
    protected CollectionsUtil() {
    }

    /**

import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;
import org.jspecify.annotations.Nullable;

/**
 * Static utility methods pertaining to the {@link Future} interface.
 *
 * <p>Many of these methods use the {@link ListenableFuture} API; consult the Guava User Guide

import java.util.concurrent.CopyOnWriteArraySet;
import java.util.stream.Collector;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * Static utility methods pertaining to {@link Set} instances. Also see this class's counterparts
 * {@link Lists}, {@link Maps} and {@link Queues}.
 *
 * <p>See the Guava User Guide article on <a href=

import java.util.Objects;
import java.util.PriorityQueue;
import java.util.Queue;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * This class contains static utility methods that operate on or return objects of type {@link
 * Iterator}. Except as noted, each method has a corresponding {@link Iterable}-based method in the
 * {@link Iterables} class.
 *