private final Callable<T> delegate;

    WrappedCallable(Callable<T> delegate) {
      this.delegate = delegate;
    }

    @Override
    public T call() throws Exception {
      return delegate.call();
    }
  }

  private static final class WrappedRunnable implements Runnable {
    private final Runnable delegate;

    WrappedRunnable(Runnable delegate) {

    @ParametricNullness final K key;
    Collection<V> delegate;
    final @Nullable WrappedCollection ancestor;
    final @Nullable Collection<V> ancestorDelegate;

    WrappedCollection(
        @ParametricNullness K key, Collection<V> delegate, @Nullable WrappedCollection ancestor) {
      this.key = key;
      this.delegate = delegate;
      this.ancestor = ancestor;

  /**
   * Returns the backing delegate instance that methods are forwarded to. Abstract subclasses
   * generally override this method with an abstract method that has a more specific return type,
   * such as {@link ForwardingSet#delegate}. Concrete subclasses override this method to supply the
   * instance being decorated.
   */
  protected abstract Object delegate();

  }

  private final Map<Class<? extends @NonNull B>, B> delegate;

  private MutableClassToInstanceMap(Map<Class<? extends @NonNull B>, B> delegate) {
    this.delegate = checkNotNull(delegate);
  }

  @Override
  protected Map<Class<? extends @NonNull B>, B> delegate() {
    return delegate;
  }

  /**

  @Override
  protected abstract SortedMap<K, V> delegate();

  @Override
  public @Nullable Comparator<? super K> comparator() {
    return delegate().comparator();
  }

  @Override
  @ParametricNullness
  public K firstKey() {
    return delegate().firstKey();
  }

  @Override
  public SortedMap<K, V> headMap(@ParametricNullness K toKey) {
    return delegate().headMap(toKey);
  }

  @Override

        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

  private static <K, V> ListMultimap<K, V> wrap(ListMultimap<K, V> delegate) {
    return new ForwardingListMultimap<K, V>() {
      @Override
      protected ListMultimap<K, V> delegate() {
        return delegate;
      }
    };
  }

    this.inverse = (ImmutableBiMap<V, K>) this;
  }

  RegularImmutableBiMap(ImmutableMap<K, V> delegate) {
    super(delegate);

    ImmutableMap.Builder<V, K> builder = ImmutableMap.builder();
    for (Entry<K, V> entry : delegate.entrySet()) {
      builder.put(entry.getValue(), entry.getKey());
    }
    ImmutableMap<V, K> backwardMap = builder.build();

        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

  private static <K, V> ListMultimap<K, V> wrap(ListMultimap<K, V> delegate) {
    return new ForwardingListMultimap<K, V>() {
      @Override
      protected ListMultimap<K, V> delegate() {
        return delegate;
      }
    };
  }

        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

  private static <K, V> SetMultimap<K, V> wrap(SetMultimap<K, V> delegate) {
    return new ForwardingSetMultimap<K, V>() {
      @Override
      protected SetMultimap<K, V> delegate() {
        return delegate;
      }
    };
  }

        .testEquals();
  }

  private static <K, V> SortedSetMultimap<K, V> wrap(SortedSetMultimap<K, V> delegate) {
    return new ForwardingSortedSetMultimap<K, V>() {
      @Override
      protected SortedSetMultimap<K, V> delegate() {
        return delegate;
      }
    };
  }