}

  @GwtIncompatible // java.util.BitSet
  private static BitSet bitSet(String chars) {
    return bitSet(chars.toCharArray());
  }

  @GwtIncompatible // java.util.BitSet
  private static BitSet bitSet(char[] chars) {
    BitSet tmp = new BitSet();
    for (char c : chars) {
      tmp.set(c);
    }
    return tmp;
  }

        table = (BitSet) table.clone();
        // If only we could actually call BitSet.trimToSize() ourselves...
      }
      this.table = table;
    }

    @Override
    public boolean matches(char c) {
      return table.get(c);
    }

    @Override
    void setBits(BitSet bitSet) {
      bitSet.or(table);
    }
  }

  // Static constant implementation classes

        table = (BitSet) table.clone();
        // If only we could actually call BitSet.trimToSize() ourselves...
      }
      this.table = table;
    }

    @Override
    public boolean matches(char c) {
      return table.get(c);
    }

    @Override
    void setBits(BitSet bitSet) {
      bitSet.or(table);
    }
  }

  // Static constant implementation classes

        }
        return false;
      }

      @Override
      public Iterator<Set<E>> iterator() {
        return new AbstractIterator<Set<E>>() {
          final BitSet bits = new BitSet(index.size());

          @Override
          protected @Nullable Set<E> computeNext() {
            if (bits.isEmpty()) {
              bits.set(0, size);
            } else {

    // Serial form:
    // 1 signed byte for the strategy
    // 1 unsigned byte for the number of hash functions
    // 1 big endian int, the number of longs in our bitset
    // N big endian longs of our bitset
    DataOutputStream dout = new DataOutputStream(out);
    dout.writeByte(SignedBytes.checkedCast(strategy.ordinal()));

        }
        return false;
      }

      @Override
      public Iterator<Set<E>> iterator() {
        return new AbstractIterator<Set<E>>() {
          final BitSet bits = new BitSet(index.size());

          @Override
          protected @Nullable Set<E> computeNext() {
            if (bits.isEmpty()) {
              bits.set(0, size);
            } else {

      }
    }

    private @Nullable Object[] lastEntryForEachKey(
        @Nullable Object[] localAlternatingKeysAndValues, int size) {
      Set<Object> seenKeys = new HashSet<>();
      BitSet dups = new BitSet(); // slots that are overridden by a later duplicate key
      for (int i = size - 1; i >= 0; i--) {
        Object key = requireNonNull(localAlternatingKeysAndValues[2 * i]);
        if (!seenKeys.add(key)) {

     * {@code null} is returned.
     */
    private static <K, V> Entry<K, V> @Nullable [] lastEntryForEachKey(
        Entry<K, V>[] entries, int size) {
      Set<K> seen = new HashSet<>();
      BitSet dups = new BitSet(); // slots that are overridden by a later duplicate key
      for (int i = size - 1; i >= 0; i--) {
        if (!seen.add(entries[i].getKey())) {
          dups.set(i);
        }
      }

    assertTrue(ArbitraryInstances.get(BitSet.class).isEmpty());
    assertTrue(ArbitraryInstances.get(TreeSet.class).isEmpty());
    assertTrue(ArbitraryInstances.get(TreeMap.class).isEmpty());
    assertFreshInstanceReturned(
        LinkedList.class,
        Deque.class,
        Queue.class,
        PriorityQueue.class,
        BitSet.class,
        TreeSet.class,
        TreeMap.class);
  }

    assertTrue(ArbitraryInstances.get(BitSet.class).isEmpty());
    assertTrue(ArbitraryInstances.get(TreeSet.class).isEmpty());
    assertTrue(ArbitraryInstances.get(TreeMap.class).isEmpty());
    assertFreshInstanceReturned(
        LinkedList.class,
        Deque.class,
        Queue.class,
        PriorityQueue.class,
        BitSet.class,
        TreeSet.class,
        TreeMap.class);
  }