}
    }

    final boolean wasInterrupted;
    @CheckForNull final Throwable cause;

    Cancellation(boolean wasInterrupted, @CheckForNull Throwable cause) {
      this.wasInterrupted = wasInterrupted;
      this.cause = cause;
    }
  }

  /** A special value that encodes the 'setFuture' state. */

              size,
              (e1, e2) -> {
                // requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);
                return comparator.compare(e1.getKey(), e2.getKey());
              });
          // requireNonNull is safe because the first `size` elements have been filled in.

   * the discussion in the {@link ListenableFuture#addListener ListenableFuture.addListener}
   * documentation.
   */
  public void add(Runnable runnable, Executor executor) {
    // Fail fast on a null. We throw NPE here because the contract of Executor states that it throws
    // NPE on null listener, so we propagate that contract up into the add method as well.
    checkNotNull(runnable, "Runnable was null.");

    UnmodifiableMultiset(Multiset<? extends E> delegate) {
      this.delegate = delegate;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected Multiset<E> delegate() {
      // This is safe because all non-covariant methods are overridden
      return (Multiset<E>) delegate;
    }

    @LazyInit @CheckForNull transient Set<E> elementSet;

    Set<E> createElementSet() {

   * cases where {@link Collection#contains} might throw {@link NullPointerException} or {@link
   * ClassCastException}.
   */
  // <? extends @Nullable Object> instead of <?> because of Kotlin b/189937072, discussed in Joiner.
  public static boolean contains(
      Iterable<? extends @Nullable Object> iterable, @CheckForNull Object element) {
    if (iterable instanceof Collection) {

  }

  /**
   * Returns the empty multimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableSetMultimap<K, V> of() {
    return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;
  }

    return CollectCollectors.toImmutableSet();
  }

  /**
   * Returns the empty immutable set. Preferred over {@link Collections#emptySet} for code
   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */

     * not allowed, and will cause {@link #build} to fail.
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> put(K key, V value) {
      super.put(key, value);
      return this;
    }

    /**
     * Adds the given {@code entry} to the bimap. Duplicate keys or values are not allowed, and will
     * cause {@link #build} to fail.
     *
     * @since 19.0

      result.descendingSet = this;
    }
    return result;
  }

  // Most classes should implement this as new DescendingImmutableSortedSet<E>(this),
  // but we push down that implementation because ProGuard can't eliminate it even when it's always
  // overridden.
  @GwtIncompatible // NavigableSet
  abstract ImmutableSortedSet<E> createDescendingSet();

  /** @since 12.0 */
  @GwtIncompatible // NavigableSet

      // independent of the initial capacity, except that it won't be lower than the threshold
      // computed from that capacity. Because the internal table is only allocated on the first
      // write, we won't see copying because of the new threshold. So it is always OK to use the
      // calculation here.
      return (int) Math.ceil(expectedSize / 0.75);
    }