}

  public void testKeySet() {
    Map<String, Integer> map = create();
    Set<String> keySet = map.keySet();
    assertTrue(keySet instanceof SynchronizedSet);
    assertSame(mutex, ((SynchronizedSet<?>) keySet).mutex);
  }

  public void testValues() {
    Map<String, Integer> map = create();
    Collection<Integer> values = map.values();

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkState;
import static java.util.Collections.synchronizedSet;
import static java.util.Collections.unmodifiableSet;

import com.google.common.base.Equivalence;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;

/**
 * Fetches HTML from a requested URL, follows the links, and repeats.
 */
public final class Crawler {
  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;

              numSuccessfulSetCalls.incrementAndGet();
            }
            awaitUnchecked(barrier);
            return null;
          }
        };
    Set<Object> finalResults = Collections.synchronizedSet(Sets.newIdentityHashSet());
    Runnable collectResultsRunnable =
        new Runnable() {
          @Override
          public void run() {
            try {

              numSuccessfulSetCalls.incrementAndGet();
            }
            awaitUnchecked(barrier);
            return null;
          }
        };
    Set<Object> finalResults = Collections.synchronizedSet(Sets.newIdentityHashSet());
    Runnable collectResultsRunnable =
        new Runnable() {
          @Override
          public void run() {
            try {

    protected Map<String, Supplier<String>> updateConfigListenerMap = new HashMap<>();

    /** A set of names of threads that are currently waiting. */
    protected Set<String> waitingThreadNames = Collections.synchronizedSet(new HashSet<>());

    /**
     * Initializes the SystemHelper.
     * This method sets up system properties, caches, and other initial configurations.
     */
    @PostConstruct
    public void init() {