fail("Should fail on null equal object");
    } catch (NullPointerException e) {
    }
  }

  /** Test adding null equal object yields error */
  public void testAddNullEqualObject() {
    try {
      equalsTester.addEqualityGroup(reference, (Object[]) null);
      fail("Should fail on null equal object");
    } catch (NullPointerException e) {
    }
  }

  /**

    Object unused1 = new Object() {};
    Object unused2 = new Object() {};
    Object unused3 = new Object() {};
    Object unused4 = new Object() {};
    Object unused5 = new Object() {};
    Object unused6 = new Object() {};
    Object unused7 = new Object() {};
    Object unused8 = new Object() {};
    Object unused9 = new Object() {};
    Object o10 = new Object() {};

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>

      MapMakerInternalMap<Object, Object, ?, ?> map = makeMap(maker);
      Segment<Object, Object, ?, ?> segment = map.segments[0];

      Object keyOne = new Object();
      Object valueOne = new Object();
      int hashOne = map.hash(keyOne);
      InternalEntry<Object, Object, ?> entryOne = segment.newEntryForTesting(keyOne, hashOne, null);
      WeakValueReference<Object, Object, ?> valueRefOne =

      MapMakerInternalMap<Object, Object, ?, ?> map = makeMap(maker);
      Segment<Object, Object, ?, ?> segment = map.segments[0];

      Object keyOne = new Object();
      Object valueOne = new Object();
      int hashOne = map.hash(keyOne);
      InternalEntry<Object, Object, ?> entryOne = segment.newEntryForTesting(keyOne, hashOne, null);
      WeakValueReference<Object, Object, ?> valueRefOne =

   */
  protected int standardCount(@CheckForNull Object object) {
    for (Entry<?> entry : this.entrySet()) {
      if (Objects.equal(entry.getElement(), object)) {
        return entry.getCount();
      }
    }
    return 0;
  }

  /**
   * A sensible definition of {@link #add(Object)} in terms of {@link #add(Object, int)}. If you

        @J2ktIncompatible // serialization
        Object writeReplace() {
          return super.writeReplace();
        }
      };
    }

    @Override
    public boolean contains(@CheckForNull Object object) {
      if (object instanceof Entry) {
        Entry<?, ?> entry = (Entry<?, ?>) object;
        Object k = entry.getKey();
        Object v = entry.getValue();

      extends View<K, V, Entry<V, K>> {
    InverseEntrySet(HashBiMap<K, V> biMap) {
      super(biMap);
    }

    @Override
    public boolean contains(@CheckForNull Object o) {
      if (o instanceof Entry) {
        Entry<?, ?> e = (Entry<?, ?>) o;
        Object v = e.getKey();
        Object k = e.getValue();

   *
   * @since 20.0 (varargs overload since 2.0)
   */
  @CanIgnoreReturnValue
  public static <T> T checkNotNull(
      @CheckForNull T reference,
      String errorMessageTemplate,
      @CheckForNull Object p1,
      @CheckForNull Object p2,
      @CheckForNull Object p3,
      @CheckForNull Object p4) {
    if (reference == null) {

   */
  protected boolean standardEquals(@CheckForNull Object object) {
    if (object instanceof Entry) {
      Entry<?, ?> that = (Entry<?, ?>) object;
      return Objects.equal(this.getKey(), that.getKey())
          && Objects.equal(this.getValue(), that.getValue());
    }
    return false;
  }

  /**
   * A sensible definition of {@link #hashCode()} in terms of {@link #getKey()} and {@link