/**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableWeakReference(@CheckForNull T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();
  }

import java.util.Collection;
import java.util.Iterator;
import java.util.Queue;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link Synchronized#queue} and {@link Queues#synchronizedQueue}.
 *
 * @author Kurt Alfred Kluever
 */
public class SynchronizedQueueTest extends TestCase {

  protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Deque;
import java.util.Iterator;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A deque which forwards all its method calls to another deque. Subclasses should override one or
 * more methods to modify the behavior of the backing deque as desired per the <a

import java.util.NoSuchElementException;
import java.util.Queue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A queue which forwards all its method calls to another queue. Subclasses should override one or
 * more methods to modify the behavior of the backing queue as desired per the <a

 */
public final class Crawler {
  private final OkHttpClient client;
  private final Set<HttpUrl> fetchedUrls = Collections.synchronizedSet(new LinkedHashSet<>());
  private final LinkedBlockingQueue<HttpUrl> queue = new LinkedBlockingQueue<>();
  private final ConcurrentHashMap<String, AtomicInteger> hostnames = new ConcurrentHashMap<>();

  public Crawler(OkHttpClient client) {
    this.client = client;
  }

import java.util.Queue;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates queues, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestQueueGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override
  Queue<E> create(Object... elements);

  public void testPoll_empty() {
    assertNull("emptyQueue.poll() should return null", getQueue().poll());
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testPoll_size1() {
    assertEquals("size1Queue.poll() should return first element", e0(), getQueue().poll());
    expectMissing(e0());
  }

        InternalEntry<Object, Object, ?> entry = segment.getEntry(keyOne, hashOne);

        @SuppressWarnings("unchecked")
        Reference<Object> reference = (Reference<Object>) entry;
        reference.enqueue();

        map.put(keyTwo, valueTwo);
        assertFalse(map.containsKey(keyOne));
        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));
        assertEquals(1, map.size());

        InternalEntry<Object, Object, ?> entry = segment.getEntry(keyOne, hashOne);

        @SuppressWarnings("unchecked")
        Reference<Object> reference = (Reference<Object>) entry;
        reference.enqueue();

        map.put(keyTwo, valueTwo);
        assertFalse(map.containsKey(keyOne));
        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));
        assertEquals(1, map.size());

import com.google.common.collect.Lists;
import com.google.common.util.concurrent.AbstractFutureBenchmarks.OldAbstractFuture;
import com.google.errorprone.annotations.concurrent.GuardedBy;
import java.util.Queue;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;