this.values = new @Nullable Object[initialCapacity];
    }

    private void ensureCapacity(int minCapacity) {
      if (minCapacity > keys.length) {
        int newCapacity = ImmutableCollection.Builder.expandedCapacity(keys.length, minCapacity);
        this.keys = Arrays.copyOf(keys, newCapacity);
        this.values = Arrays.copyOf(values, newCapacity);
      }
    }

    /**

      synchronized (mutex) {
        return delegate().size();
      }
    }

    @Override
    public Collection<V> values() {
      synchronized (mutex) {
        if (values == null) {
          values = collection(delegate().values(), mutex);
        }
        return values;
      }
    }

    @Override
    public boolean equals(@CheckForNull Object o) {
      if (o == this) {

                    return Sets.union(set1, set2);
                  }
                })
            .named("Sets.union")
            .withFeatures(CollectionSize.ANY, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override

    ensureNotDirectlyModifiable(unmod.tailMap(2, true));

    Collection<String> values = unmod.values();
    try {
      values.add("4");
      fail("UnsupportedOperationException expected");
    } catch (UnsupportedOperationException expected) {
    }
    try {
      values.remove("four");
      fail("UnsupportedOperationException expected");

    ensureNotDirectlyModifiable(unmod.tailMap(2, true));

    Collection<String> values = unmod.values();
    try {
      values.add("4");
      fail("UnsupportedOperationException expected");
    } catch (UnsupportedOperationException expected) {
    }
    try {
      values.remove("four");
      fail("UnsupportedOperationException expected");

  }

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableSortedMap} whose
   * keys and values are the result of applying the provided mapping functions to the input
   * elements.
   *
   * <p>If the mapped keys contain duplicates (according to the comparator), the values are merged
   * using the specified merging function. Entries will appear in the encounter order of the first
   * occurrence of the key.

    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet());
  }

  @LazyInit @CheckForNull transient Collection<V> values;

  @Override
  public Collection<V> values() {
    Collection<V> vs = values;
    return (vs != null) ? vs : (values = new Values());
  }

  @LazyInit @CheckForNull transient Set<Entry<K, V>> entrySet;

  @Override
  public Set<Entry<K, V>> entrySet() {

    public Collection<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
      throw new UnsupportedOperationException();
    }

    @Override
    public Collection<V> values() {
      Collection<V> result = values;
      if (result == null) {
        values = result = Collections.unmodifiableCollection(delegate.values());
      }
      return result;
    }

      super(5, MODIFIABLE, newArrayList(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER);
    }
  }

  private static Iterator<Integer> iterateOver(int... values) {
    // Note: Ints.asList's iterator does not support remove which we need for testing.
    return new ArrayList<>(Ints.asList(values)).iterator();
  }

  public void testElementsEqual() {
    Iterable<?> a;
    Iterable<?> b;

    // Base case.

   *
   * <p>Weak values will be garbage collected once they are weakly reachable. This makes them a poor
   * candidate for caching; consider {@link #softValues} instead.
   *
   * <p><b>Note:</b> when this method is used, the resulting cache will use identity ({@code ==})
   * comparison to determine equality of values.
   *