*/
  @Override
  public ImmutableSet<K> keySet() {
    ImmutableSet<K> result = keySet;
    return (result == null) ? keySet = createKeySet() : result;
  }

  /*
   * This could have a good default implementation of return new ImmutableKeySet<K, V>(this),
   * but ProGuard can't figure out how to eliminate that default when RegularImmutableMap
   * overrides it.
   */

      val streamsCopy: Array<Http2Stream>
      withLock {
        streamsCopy = streams.values.toTypedArray()
        isShutdown = true
      }

      // Fail all streams created after the last good stream ID.
      for (http2Stream in streamsCopy) {
        if (http2Stream.id > lastGoodStreamId && http2Stream.isLocallyInitiated) {
          http2Stream.receiveRstStream(REFUSED_STREAM)

   * Returns a new builder with a hint for how many distinct keys are expected to be added. The
   * generated builder is equivalent to that returned by {@link #builder}, but may perform better if
   * {@code expectedKeys} is a good estimate.
   *
   * @throws IllegalArgumentException if {@code expectedKeys} is negative
   * @since 33.3.0
   */
  public static <K, V> Builder<K, V> builderWithExpectedKeys(int expectedKeys) {

   * @since 10.0
   */
  public static String toAddrString(InetAddress ip) {
    checkNotNull(ip);
    if (ip instanceof Inet4Address) {
      // For IPv4, Java's formatting is good enough.
      // requireNonNull accommodates Android's @RecentlyNullable annotation on getHostAddress
      return requireNonNull(ip.getHostAddress());
    }
    byte[] bytes = ip.getAddress();

## Version 4.2.1

_2019-10-02_

 *  Fix: In 4.1.0 we introduced a performance regression that prevented connections from being
    pooled in certain situations. We have good test coverage for connection pooling but we missed
    this because it only occurs if you have proxy configured and you share a connection pool among
    multiple `OkHttpClient` instances.

        if (type == 0) {
            if (getUncPath0().length() > 1) {
                type = TYPE_FILESYSTEM;
            } else if (share != null) {
                // treeConnect good enough to test service type
                connect0();
                if (share.equals("IPC$")) {
                    type = TYPE_NAMED_PIPE;
                } else if (tree.service.equals("LPT1:")) {

   * Returns a new builder with a hint for how many distinct keys are expected to be added. The
   * generated builder is equivalent to that returned by {@link #builder}, but may perform better if
   * {@code expectedKeys} is a good estimate.
   *
   * @throws IllegalArgumentException if {@code expectedKeys} is negative
   * @since 33.3.0
   */
  public static <K, V> Builder<K, V> builderWithExpectedKeys(int expectedKeys) {

        .build(),
    )
    server.enqueue(
      MockResponse(body = "abc"),
    )
    // Enqueue an additional response that show if we burnt a good prior response.
    server.enqueue(
      MockResponse(body = "XXX"),
    )
    val call1 = client.newCall(Request(server.url("/")))
    val response1 = call1.execute()

    websocket messages will be delivered. The `onFailure()` method now includes
    an HTTP response if one was returned.

## Version 2.4.0-RC1

_2015-05-16_

 *  **New HttpUrl API.** It's like `java.net.URL` but good. Note that
    `Request.Builder.url()` now throws `IllegalArgumentException` on malformed
    URLs. (Previous releases would throw a `MalformedURLException` when calling
    a malformed URL.)

   * @since 21.0
   */
  public static float constrainToRange(float value, float min, float max) {
    // avoid auto-boxing by not using Preconditions.checkArgument(); see Guava issue 3984
    // Reject NaN by testing for the good case (min <= max) instead of the bad (min > max).
    if (min <= max) {
      return Math.min(Math.max(value, min), max);
    }
    throw new IllegalArgumentException(