// GWT's ConcurrentHashMap is a wrapper around HashMap, but it rejects null keys, which matches
    // the behaviour of the non-GWT implementation of newConcurrentHashSet().
    // On the other hand HashSet might be better for code size if apps aren't
    // already using Collections.newSetFromMap and ConcurrentHashMap.
    return Collections.newSetFromMap(new ConcurrentHashMap<E, Boolean>());
  }

  private final OkHttpClient client;
  private final Set<HttpUrl> fetchedUrls = Collections.synchronizedSet(new LinkedHashSet<>());
  private final BlockingQueue<HttpUrl> queue;
  private final ConcurrentHashMap<String, AtomicInteger> hostnames = new ConcurrentHashMap<>();
  private final int hostLimit;

  public Crawler(OkHttpClient client, int queueLimit, int hostLimit) {
    this.client = client;
    this.queue = new LinkedBlockingQueue<>(queueLimit);

   * what to do with <a
   * href="https://github.com/openjdk/jdk/blob/c25c4896ad9ef031e3cddec493aef66ff87c48a7/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java#L4830">{@code
   * ConcurrentHashMap} support for {@code entrySet().add()}</a>.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddUnsupportedNotPresentMethod() {

   * what to do with <a
   * href="https://github.com/openjdk/jdk/blob/c25c4896ad9ef031e3cddec493aef66ff87c48a7/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java#L4830">{@code
   * ConcurrentHashMap} support for {@code entrySet().add()}</a>.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddUnsupportedNotPresentMethod() {

     * @param value the value to be added to the <code>Map</code>
     * @return a {@literal Maps} for constructing a {@link ConcurrentHashMap} with the specified key and value
     */
    public static <KEY, VALUE> Maps<KEY, VALUE> concurrentHashMap(final KEY key, final VALUE value) {
        return new Maps<>(new ConcurrentHashMap<KEY, VALUE>()).$(key, value);
    }

    /**

   * figure out what to do with <a
   * href="https://github.com/openjdk/jdk/blob/c25c4896ad9ef031e3cddec493aef66ff87c48a7/src/java.base/share/classes/java/util/concurrent/ConcurrentHashMap.java#L4830">{@code
   * ConcurrentHashMap} support for {@code entrySet().add()}</a>.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static Method getAddAllUnsupportedNonePresentMethod() {

 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkArgument;

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/**
 * MapMaker emulation.
 *
 * @author Charles Fry
 */
public final class MapMaker {
  private int initialCapacity = 16;

  public MapMaker() {}

import com.google.common.base.Function;
import com.google.common.testing.NullPointerTester;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * @author Charles Fry
 */
@GwtCompatible
@J2ktIncompatible // MapMaker

import com.google.common.base.Function;
import com.google.common.primitives.Ints;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;

import java.net.InetSocketAddress
import java.net.ProtocolException
import java.net.Proxy
import java.net.ServerSocket
import java.net.Socket
import java.net.SocketException
import java.util.concurrent.ConcurrentHashMap
import java.util.concurrent.Executors
import java.util.concurrent.TimeUnit
import java.util.concurrent.atomic.AtomicInteger
import java.util.logging.Level
import java.util.logging.Logger