public int[] call() throws Exception {
      int iterations = 100000;
      int nKeys = keys.size();
      int[] deltas = new int[nKeys];
      Operation[] operations = Operation.values();
      for (int i = 0; i < iterations; i++) {
        int keyIndex = random.nextInt(nKeys);
        String key = keys.get(keyIndex);
        Operation op = operations[random.nextInt(operations.length)];
        switch (op) {
          case ADD:

 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and
 * amortized) constant time operations. Expected in the hashtable sense (depends on the hash

   * optionally including {@code upperBound} itself. The returned multiset is a view of this
   * multiset, so changes to one will be reflected in the other. The returned multiset supports all
   * operations that this multiset supports.
   *
   * <p>The returned multiset will throw an {@link IllegalArgumentException} on attempts to add
   * elements outside its range.
   */

 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)
 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a

   * listeners are also applicable to heavyweight functions passed to this method. (Specifically,
   * {@code directExecutor} functions should avoid heavyweight operations inside {@code
   * AsyncFunction.apply}. Any heavyweight operations should occur in other threads responsible for
   * completing the returned {@code Future}.)
   *

 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedListMultimap}.
 *
 * <p>See the Guava User Guide article on <a href=

      SUPPORTS_SET,
      SUPPORTS_ADD_WITH_INDEX,
      SUPPORTS_REMOVE_WITH_INDEX),

  /** Features supported by lists where only removal is allowed. */
  REMOVE_OPERATIONS(CollectionFeature.REMOVE_OPERATIONS, SUPPORTS_REMOVE_WITH_INDEX);

  private final Set<Feature<? super List>> implied;

  ListFeature(Feature<? super List>... implied) {
    this.implied = Helpers.copyToSet(implied);
  }

public final class ConcurrentHashMultiset<E> extends AbstractMultiset<E> implements Serializable {

  /*
   * The ConcurrentHashMultiset's atomic operations are implemented primarily in terms of
   * AtomicInteger's atomic operations, with some help from ConcurrentMap's atomic operations on
   * creation and removal (including automatic removal of zeroes). If the modification of an

     */

    public static final int PIPE_TYPE_RDWR = SmbConstants.O_RDWR;

    /**
     * Pipe operations should behave like the <code>CallNamedPipe</code> Win32 Named Pipe function.
     */

    public static final int PIPE_TYPE_CALL = 0x0100;

    /**
     * Pipe operations should behave like the <code>TransactNamedPipe</code> Win32 Named Pipe function.
     */

    implements Multiset<E> {
  // Query Operations

  @Override
  public boolean isEmpty() {
    return entrySet().isEmpty();
  }

  @Override
  public boolean contains(@CheckForNull Object element) {
    return count(element) > 0;
  }

  // Modification Operations
  @CanIgnoreReturnValue
  @Override
  public final boolean add(@ParametricNullness E element) {