public static <V extends @Nullable Object> ListenableFuture<V> immediateCancelledFuture() {
    ListenableFuture<Object> instance = ImmediateCancelledFuture.INSTANCE;
    if (instance != null) {
      return (ListenableFuture<V>) instance;
    }
    return new ImmediateCancelledFuture<>();
  }

  /**

 * documented. Exceptions to this are {@link #containsKey}, {@link #size}, {@link #isEmpty}, {@link
 * #asMap}, and {@link #toString}.
 *
 * <p>Instances of this class may be used by multiple threads concurrently. All operations are
 * atomic unless otherwise noted.
 *
 * <p>Instances of this class are serializable if the keys are serializable.
 *
 * <p><b>Note:</b> If your values are always positive and less than 2^31, you may wish to use a

 * returned.
 *
 * <p>All default instances returned by {@link #get} are generics-safe. Clients won't get type
 * errors for using {@code get(Comparator.class)} as a {@code Comparator<Foo>}, for example.
 * Immutable empty instances are returned for collection types; {@code ""} for string; {@code 0} for
 * number types; reasonable default instance for other stateless types. For mutable types, a fresh

import java.nio.ByteBuffer;
import java.util.zip.Checksum;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * {@link HashFunction} adapter for {@link Checksum} instances.
 *
 * @author Colin Decker
 */
@Immutable
@ElementTypesAreNonnullByDefault
final class ChecksumHashFunction extends AbstractHashFunction implements Serializable {

   *
   * <p>tl4j details: For backwards compatibility, {@code junit3.TearDownTestCase} currently does
   * not fail a test when an exception is thrown from one of its {@link TearDown} instances, but
   * this is subject to change. Also, {@code junit4.TearDownTestCase} will.
   *
   * @throws Exception for any reason. {@code TearDownTestCase} ensures that any exception thrown

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

/**
 * Provides static utility methods for creating and working with {@link SortedMultiset} instances.
 *
 * @author Louis Wasserman
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
final class SortedMultisets {
  private SortedMultisets() {}

            return exception instanceof UnsupportedOperationException
                || exception instanceof IllegalStateException;
          }
        };
    static final PermittedMetaException UOE =
        new PermittedMetaException("UnsupportedOperationException") {
          @Override
          boolean isPermitted(Exception exception) {
            return exception instanceof UnsupportedOperationException;
          }

/**
 * This abstract base class for testers allows the framework to inject needed information after
 * JUnit constructs the instances.
 *
 * <p>This class is emulated in GWT.
 *
 * @param <G> the type of the test generator required by this tester. An instance of G should
 *     somehow provide an instance of the class under test, plus any other information required to
 *     parameterize the test.
 * @author George van den Driessche
 */

/**
 * This abstract base class for testers allows the framework to inject needed information after
 * JUnit constructs the instances.
 *
 * <p>This class is emulated in GWT.
 *
 * @param <G> the type of the test generator required by this tester. An instance of G should
 *     somehow provide an instance of the class under test, plus any other information required to
 *     parameterize the test.
 * @author George van den Driessche
 */

  }

  @Override
  public final boolean equals(@CheckForNull Object obj) {
    if (obj instanceof Subscriber) {
      Subscriber that = (Subscriber) obj;
      // Use == so that different equal instances will still receive events.
      // We only guard against the case that the same object is registered
      // multiple times