public T orNull() {
    return null;
  }

  @Override
  public Set<T> asSet() {
    return Collections.emptySet();
  }

  @Override
  public <V> Optional<V> transform(Function<? super T, V> function) {
    checkNotNull(function);
    return Optional.absent();
  }

  @Override
  public boolean equals(@CheckForNull Object object) {
    return object == this;
  }

  @Override
  public int hashCode() {

        </ul>
        <script>
        var ws = null;
            function connect(event) {
                var itemId = document.getElementById("itemId")
                var token = document.getElementById("token")
                ws = new WebSocket("ws://localhost:8000/items/" + itemId.value + "/ws?token=" + token.value);
                ws.onmessage = function(event) {
                    var messages = document.getElementById('messages')

        </ul>
        <script>
        var ws = null;
            function connect(event) {
                var itemId = document.getElementById("itemId")
                var token = document.getElementById("token")
                ws = new WebSocket("ws://localhost:8000/items/" + itemId.value + "/ws?token=" + token.value);
                ws.onmessage = function(event) {
                    var messages = document.getElementById('messages')

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.base.Function;
import com.google.common.testing.ForwardingWrapperTester;
import java.util.ListIterator;
import junit.framework.TestCase;

/**
 * Tests for {@code ForwardingListIterator}.
 *
 * @author Robert Konigsberg
 */

import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterator.OfPrimitive;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *
 * @since NEXT (but since 21.0 in the JRE flavor)

import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterator.OfPrimitive;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *

      ListenableFuture<O> transform(
          ListenableFuture<I> input, Function<? super I, ? extends O> function, Executor executor) {
    return AbstractTransformFuture.create(input, function, executor);
  }

  /**
   * Like {@link #transform(ListenableFuture, Function, Executor)} except that the transformation
   * {@code function} is invoked on each call to {@link Future#get() get()} on the returned future.
   *

public class MapComputeIfAbsentTester<K, V> extends AbstractMapTester<K, V> {

  @MapFeature.Require(SUPPORTS_PUT)
  public void testComputeIfAbsent_supportedAbsent() {
    assertEquals(
        "computeIfAbsent(notPresent, function) should return new value",
        v3(),
        getMap()
            .computeIfAbsent(
                k3(),
                k -> {
                  assertEquals(k3(), k);
                  return v3();

  private static final String RESULT_DATA = "SUCCESS";

  private SettableFuture<String> outputFuture;
  // Signals that the function is waiting to complete
  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {

  private static final String RESULT_DATA = "SUCCESS";

  private SettableFuture<String> outputFuture;
  // Signals that the function is waiting to complete
  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {