// the behaviour of the non-GWT implementation of newConcurrentHashSet().
    // On the other hand HashSet might be better for code size if apps aren't
    // already using Collections.newSetFromMap and ConcurrentHashMap.
    return Collections.newSetFromMap(new ConcurrentHashMap<E, Boolean>());
  }

  static <E> Set<E> newLinkedHashSetWithExpectedSize(int expectedSize) {
    return Sets.newLinkedHashSetWithExpectedSize(expectedSize);
  }

   * Set<Object> identityHashSet = Sets.newSetFromMap(
   *     new IdentityHashMap<Object, Boolean>());
   * }</pre>
   *
   * <p>The returned set is serializable if the backing map is.
   *
   * @param map the backing map
   * @return the set backed by the map
   * @throws IllegalArgumentException if {@code map} is not empty
   * @deprecated Use {@link Collections#newSetFromMap} instead.
   */
  @Deprecated

  private val executor = Executors.newCachedThreadPool(threadFactory("SocksProxy"))
  private var serverSocket: ServerSocket? = null
  private val connectionCount = AtomicInteger()
  private val openSockets = Collections.newSetFromMap(ConcurrentHashMap<Socket, Boolean>())

  fun play() {
    serverSocket = ServerSocket(0)
    executor.execute {
      val threadName = "SocksProxy ${serverSocket!!.localPort}"

       * UnsignedBytesBenchmark. TODO(cpovirk): benchmark this
       */
      /*
       * A CopyOnWriteArraySet<WeakReference> is faster than a newSetFromMap of a MapMaker map with
       * weakKeys() and concurrencyLevel(1), even up to at least 12 cached exception types.
       */
      private static final Set<WeakReference<Class<? extends Exception>>> validClasses =

  }

  public void testNewSetFromMap() {
    Set<Integer> set = Sets.newSetFromMap(new HashMap<Integer, Boolean>());
    set.addAll(SOME_COLLECTION);
    verifySetContents(set, SOME_COLLECTION);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testNewSetFromMapSerialization() {
    Set<Integer> set = Sets.newSetFromMap(new LinkedHashMap<Integer, Boolean>());
    set.addAll(SOME_COLLECTION);

  private val requestQueue = LinkedBlockingQueue<RecordedRequest>()
  private val openClientSockets =
    Collections.newSetFromMap(ConcurrentHashMap<Socket, Boolean>())
  private val openConnections =
    Collections.newSetFromMap(ConcurrentHashMap<Http2Connection, Boolean>())

  private val atomicRequestCount = AtomicInteger()

  /**

  }

  public void testNewSetFromMap() {
    Set<Integer> set = Sets.newSetFromMap(new HashMap<Integer, Boolean>());
    set.addAll(SOME_COLLECTION);
    verifySetContents(set, SOME_COLLECTION);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testNewSetFromMapSerialization() {
    Set<Integer> set = Sets.newSetFromMap(new LinkedHashMap<Integer, Boolean>());
    set.addAll(SOME_COLLECTION);