* intended for use in Internationalized Domain Names (IDNs).
 *
 * This class contains a Kotlin implementation of the pseudocode specified by RFC 3492. It includes
 * direct translation of the pseudocode presented there.
 *
 * Partner this class with [UTS #46] to implement IDNA2008 [RFC 5890] like most browsers do.
 *
 * [RFC 3492]: https://datatracker.ietf.org/doc/html/rfc3492
 * [RFC 5890]: https://datatracker.ietf.org/doc/html/rfc5890

   * a default value.
   *
   * If this does read a value, it starts with the tag and length, and reads an entire value,
   * including any potential composed values.
   *
   * If there's nothing to read and no default value, this will throw an exception.
   */
  fun fromDer(reader: DerReader): T

  fun fromDer(byteString: ByteString): T {
    val buffer = Buffer().write(byteString)

Use MockWebServer the same way that you use mocking frameworks like
[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.
2. Run application code.
3. Verify that the expected requests were made.

Here's a complete example:

```java
public void test() throws Exception {
  // Create a MockWebServer. These are lean enough that you can create a new
  // instance for every unit test.

![Events Diagram](../assets/images/******@****.***)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java

The application-layer can also do blocking reads. If the application asks to read and there's nothing available, we need to hold that thread until either the bytes arrive, the stream is closed, or a timeout elapses. If we get bytes but there's nobody asking for them, we buffer them. We don't consider bytes as delivered for flow control until they're consumed by the application.

/**
 * What should be done with the incoming socket.
 *
 * Be careful when using values like [DisconnectAtEnd], [ShutdownInputAtEnd]
 * and [ShutdownOutputAtEnd] that close a socket after a response, and where there are
 * follow-up requests. The client is unblocked and free to continue as soon as it has received the
 * entire response body. If and when the client makes a subsequent request using a pooled socket the

 *
 * Specifically while junit instances passes into test constructor
 * are typically shares amongst all tests, a fresh instance will be
 * received here. Use with @BeforeAll and @AfterAll, is not supported.
 *
 * There are 3 ids for instances
 * - The test instance default (passed into constructor)
 * - The test lifecycle default (passed into test method, plus @BeforeEach, @AfterEach)

      serverSocketChannel.configureBlocking(true);
      serverSocketChannel.socket().bind(address);
    }

    @Override public int getLocalPort() {
      return 1; // A white lie. There is no local port.
    }

    @Override public SocketAddress getLocalSocketAddress() {
      return endpoint;
    }

    @Override public Socket accept() throws IOException {
      try {

import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.internal.TlsUtil.localhost

/**
 * OkHttp is usually tested with functional tests: these use public APIs to confirm behavior against
 * MockWebServer. In cases where logic is particularly tricky, we use unit tests. This class makes
 * it easy to get sample values to use in such tests.
 *
 * This class is pretty fast and loose with default values: it attempts to provide values that are

    taskRunner.lock.withLock {
      // If the queue is already idle, that's easy.
      if (activeTask == null && futureTasks.isEmpty()) {
        return CountDownLatch(0)
      }

      // If there's an existing AwaitIdleTask, use it. This is necessary when the executor is
      // shutdown but still busy as we can't enqueue in that case.
      val existingTask = activeTask
      if (existingTask is AwaitIdleTask) {