}
  }

  /** An {@code Iterator} over distinct keys in key head order. */
  private final class DistinctKeyIterator implements Iterator<K> {
    final Set<K> seenKeys = Sets.newHashSetWithExpectedSize(keySet().size());
    @Nullable Node<K, V> next = head;
    @Nullable Node<K, V> current;
    int expectedModCount = modCount;

    private void checkForConcurrentModification() {

      this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
    }

    @Override
    public Set<V> get() {
      return Platform.newHashSetWithExpectedSize(expectedValuesPerKey);
    }
  }

  private static final class LinkedHashSetSupplier<V extends @Nullable Object>
      implements Supplier<Set<V>>, Serializable {

      this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
    }

    @Override
    public Set<V> get() {
      return Platform.newHashSetWithExpectedSize(expectedValuesPerKey);
    }
  }

  private static final class LinkedHashSetSupplier<V extends @Nullable Object>
      implements Supplier<Set<V>>, Serializable {

      checkExactMatches(m, chars);
    }
  }

  static void checkExactMatches(CharMatcher m, char[] chars) {
    Set<Character> positive = Sets.newHashSetWithExpectedSize(chars.length);
    for (char c : chars) {
      positive.add(c);
    }
    for (int c = 0; c <= Character.MAX_VALUE; c++) {

   * collision rate looks sane.
   */
  static void assertInvariants(HashFunction hashFunction) {
    int objects = 100;
    Set<HashCode> hashcodes = Sets.newHashSetWithExpectedSize(objects);
    Random random = new Random(314159);
    for (int i = 0; i < objects; i++) {
      int value = random.nextInt();
      HashCode hashcode1 = hashFunction.hashInt(value);

            .build(new DelayingIdentityLoader<String>(computationShouldWait, computationLatch));

    int nThreads = 100;
    int nTasks = 1000;
    int nSeededEntries = 100;
    Set<String> expectedKeys = Sets.newHashSetWithExpectedSize(nTasks + nSeededEntries);
    // seed the map, so its segments have a count>0; otherwise, clear() won't visit the in-progress
    // entries
    for (int i = 0; i < nSeededEntries; i++) {
      String s = "b" + i;

            .build(new DelayingIdentityLoader<String>(computationShouldWait, computationLatch));

    int nThreads = 100;
    int nTasks = 1000;
    int nSeededEntries = 100;
    Set<String> expectedKeys = Sets.newHashSetWithExpectedSize(nTasks + nSeededEntries);
    // seed the map, so its segments have a count>0; otherwise, clear() won't visit the in-progress
    // entries
    for (int i = 0; i < nSeededEntries; i++) {
      String s = "b" + i;

    }
  }

  /** An {@code Iterator} over distinct keys in key head order. */
  private final class DistinctKeyIterator implements Iterator<K> {
    final Set<K> seenKeys = Sets.newHashSetWithExpectedSize(keySet().size());
    @Nullable Node<K, V> next = head;
    @Nullable Node<K, V> current;
    int expectedModCount = modCount;

    private void checkForConcurrentModification() {

    private final Set<Object> delegate;

    JdkBackedSetBuilderImpl(SetBuilderImpl<E> toCopy) {
      super(toCopy); // initializes dedupedElements and distinct
      delegate = Sets.newHashSetWithExpectedSize(distinct);
      for (int i = 0; i < distinct; i++) {
        /*
         * requireNonNull is safe because we ensure that the first `distinct` elements have been
         * populated.
         */