public final class CollectorTester<
    T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object> {
  /**
   * Creates a {@code CollectorTester} for the specified {@code Collector}. The result of the {@code
   * Collector} will be compared to the expected value using {@link Object#equals}.
   */
  public static <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>

                return (from == null) ? true : null;
              }
            });

    Set<Entry<@Nullable String, @Nullable Boolean>> entries = map.entrySet();
    assertTrue(entries.contains(Maps.immutableEntry("a", true)));
    assertTrue(entries.contains(Maps.<String, @Nullable Boolean>immutableEntry("b", null)));
    assertTrue(

            MultimapBuilder.linkedHashKeys().linkedHashSetValues()::<K, V>build),
        ImmutableSetMultimap::copyOf);
  }

  static <
          T extends @Nullable Object,
          K extends @Nullable Object,
          V extends @Nullable Object,
          M extends Multimap<K, V>>
      Collector<T, ?, M> toMultimap(
          Function<? super T, ? extends K> keyFunction,

  @Generates
  static <K, V> Map<K, V> generateMap(@Nullable K key, @Nullable V value) {
    return generateHashdMap(key, value);
  }

  @Generates
  static <K, V> HashMap<K, V> generateHashdMap(@Nullable K key, @Nullable V value) {
    return generateLinkedHashMap(key, value);
  }

  @Generates
  static <K, V> LinkedHashMap<K, V> generateLinkedHashMap(@Nullable K key, @Nullable V value) {

    }

    @Nonnull
    static SettingsBuilderRequest build(
            @Nonnull Session session,
            @Nullable Source globalSettingsSource,
            @Nullable Source projectSettingsSource,
            @Nullable Source userSettingsSource) {
        return builder()
                .session(nonNull(session, "session cannot be null"))

    }

    @Override
    Map<R, @Nullable V> getValue(int index) {
      return new Column(index);
    }

    @Override
    Map<R, @Nullable V> setValue(int index, Map<R, @Nullable V> newValue) {
      throw new UnsupportedOperationException();
    }

    @Override
    @CheckForNull
    public Map<R, @Nullable V> put(C key, Map<R, @Nullable V> value) {
      throw new UnsupportedOperationException();

   */
  @CheckForNull @LazyInit private List<@Nullable Present<V>> values;

  CollectionFuture(
      ImmutableCollection<? extends ListenableFuture<? extends V>> futures,
      boolean allMustSucceed) {
    super(futures, allMustSucceed, true);

    List<@Nullable Present<V>> values =
        futures.isEmpty()
            ? Collections.<@Nullable Present<V>>emptyList()

   */
  public static <E extends @Nullable Object> List<E> asList(
      @ParametricNullness E first, @ParametricNullness E second, E[] rest) {
    return new TwoPlusArrayList<>(first, second, rest);
  }

  /** @see Lists#asList(Object, Object[]) */
  private static class OnePlusArrayList<E extends @Nullable Object> extends AbstractList<E>
      implements Serializable, RandomAccess {

   */
  public static <K extends @Nullable Object, V extends @Nullable Object> Multimap<K, V> newMultimap(
      Map<K, Collection<V>> map, final Supplier<? extends Collection<V>> factory) {
    return new CustomMultimap<>(map, factory);
  }

  private static class CustomMultimap<K extends @Nullable Object, V extends @Nullable Object>
      extends AbstractMapBasedMultimap<K, V> {

   */
  public static <A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f) {
    return new FunctionComposition<>(g, f);
  }

  private static class FunctionComposition<
          A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      implements Function<A, C>, Serializable {