if (result == null) {
        result = INSTANCES[secondaryName(javaName)]

        if (result == null) {
          result = CipherSuite(javaName)
        }

        // Add the new cipher suite, or a confirmed alias.
        INSTANCES[javaName] = result
      }
      return result
    }

    private fun secondaryName(javaName: String): String {
      return when {

 *  Fix: Permit multipart file names to contain non-ASCII characters.
 *  New: API to get MockWebServer's dispatcher.
 *  New: API to access headers as `java.time.Instant`.
 *  New: Fail fast if a `SSLSocketFactory` is used as a `SocketFactory`.
 *  New: Log the TLS handshake in `LoggingEventListener`.

## Version 3.12.13

_2021-01-30_

    final ConnectionSpec spec = new ConnectionSpec.Builder(ConnectionSpec.MODERN_TLS)
        .cipherSuites(customCipherSuites.toArray(new CipherSuite[0]))
        .build();

    X509TrustManager trustManager = defaultTrustManager();
    SSLSocketFactory sslSocketFactory = defaultSslSocketFactory(trustManager);
    SSLSocketFactory customSslSocketFactory = new DelegatingSSLSocketFactory(sslSocketFactory) {

public final class PrintEvents {
  private final OkHttpClient client = new OkHttpClient.Builder()
      .eventListenerFactory(PrintingEventListener.FACTORY)
      .build();

  public void run() throws Exception {
    Request washingtonPostRequest = new Request.Builder()
        .url("https://www.washingtonpost.com/")
        .build();
    client.newCall(washingtonPostRequest).enqueue(new Callback() {

  private static final MediaType MEDIA_TYPE_PNG = MediaType.get("image/png");

  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    // Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image
    RequestBody requestBody = new MultipartBody.Builder()
        .setType(MultipartBody.FORM)
        .addFormDataPart("title", "Square Logo")

public final class SynchronousGet {
  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/helloworld.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

    }

    RtmSession rtmSession = new RtmSession(slackApi);
    rtmSession.open(accessToken);
  }

  public static void main(String... args) throws Exception {
    String clientId = "0000000000.00000000000";
    String clientSecret = "00000000000000000000000000000000";
    int port = 53203;
    SlackApi slackApi = new SlackApi(clientId, clientSecret, port);

    SlackClient client = new SlackClient(slackApi);

  private static final Logger logger = Logger.getLogger(LoggingInterceptors.class.getName());
  private final OkHttpClient client = new OkHttpClient.Builder()
      .addInterceptor(new LoggingInterceptor())
      .build();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/helloworld.txt")
        .build();

has been replaced with a new synthetic header, `OkHttp-Selected-Protocol`.

##### Changes

 * New: Support for `HTTP-draft-09/2.0`.
 * New: Support for `spdy/3.1`. Dropped support for `spdy/3`.
 * New: Use ALPN on Android platforms that support it (4.4+)
 * New: CacheControl model and parser.
 * New: Protocol selection in MockWebServer.

public class PostExample {
  public static final MediaType JSON = MediaType.get("application/json; charset=utf-8");

  final OkHttpClient client = new OkHttpClient();

  String post(String url, String json) throws IOException {
    RequestBody body = RequestBody.create(json, JSON);
    Request request = new Request.Builder()
        .url(url)
        .post(body)
        .build();
    try (Response response = client.newCall(request).execute()) {