@ElementTypesAreNonnullByDefault
public abstract class AbstractListeningExecutorService extends AbstractExecutorService
    implements ListeningExecutorService {

  /**
   * @since 19.0 (present with return type {@code ListenableFutureTask} since 14.0)
   */
  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  protected final <T extends @Nullable Object> RunnableFuture<T> newTaskFor(

/** An ordering that treats {@code null} as less than all other values. */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
final class NullsFirstOrdering<T extends @Nullable Object> extends Ordering<@Nullable T>
    implements Serializable {
  final Ordering<? super T> ordering;

  NullsFirstOrdering(Ordering<? super T> ordering) {
    this.ordering = ordering;
  }

  @Override

     * @since 19.0
     */
    @CanIgnoreReturnValue
    public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
      if (entries instanceof Collection) {
        ensureCapacity(size + ((Collection<?>) entries).size());
      }
      for (Entry<? extends K, ? extends V> entry : entries) {
        put(entry);
      }
      return this;
    }

    /**

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@ElementTypesAreNonnullByDefault
public abstract class AbstractMultimapTester<
        K extends @Nullable Object, V extends @Nullable Object, M extends Multimap<K, V>>
    extends AbstractContainerTester<M, Entry<K, V>> {

  private M multimap;

  protected M multimap() {
    return multimap;
  }

  /**

        final V value = parent.remove(key);
        if (value != null) {
            return value;
        }
        return parent.remove(key);
    }

    @Override
    public void putAll(final Map<? extends K, ? extends V> m) {
        parent.putAll(m);
    }

    @Override
    public void clear() {
        parent.clear();
    }

    @Override
    public Set<K> keySet() {

    // used under GWT, etc., since the override of this method does not exist there
    ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
      return ImmutableMap.of();
    }
  }

  private static final ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> INSTANCE_OF =
      ImmutableMap.<Class<? extends Throwable>, Predicate<Throwable>>builder()

  @Override
  protected List<Class<? extends AbstractTester>> getTesters() {
    List<Class<? extends AbstractTester>> testers = copyToList(super.getTesters());
    testers.add(NavigableMapNavigationTester.class);
    return testers;
  }

  @Override
  protected List<TestSuite> createDerivedSuites(
      FeatureSpecificTestSuiteBuilder<
              ?, ? extends OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>>>

    // used under GWT, etc., since the override of this method does not exist there
    ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> exceptions() {
      return ImmutableMap.of();
    }
  }

  private static final ImmutableMap<Class<? extends Throwable>, Predicate<Throwable>> INSTANCE_OF =
      ImmutableMap.<Class<? extends Throwable>, Predicate<Throwable>>builder()

      return INSTANCE;
    }

    private static final long serialVersionUID = 0;
  }

  static <C extends Comparable> Cut<C> belowValue(C endpoint) {
    return new BelowValue<>(endpoint);
  }

  private static final class BelowValue<C extends Comparable> extends Cut<C> {
    BelowValue(C endpoint) {
      super(checkNotNull(endpoint));
    }

    @Override

    }
  }

  public static class ImmutableMapCopyOfEntriesGenerator extends TestStringMapGenerator {
    @Override
    protected Map<String, String> create(Entry<String, String>[] entries) {
      return ImmutableMap.copyOf(asList(entries));
    }
  }

  public static class ImmutableMapUnhashableValuesGenerator
      extends TestUnhashableCollectionGenerator<Collection<UnhashableObject>> {

    @Override