fun request(): Request

  /**
   * Immediately and violently release resources held by this event source. This does nothing if
   * the event source has already been closed or canceled.
   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an

 * returns the same bytes as the upstream source. Downstream sources may read data either as it
 * is returned by upstream, or after the upstream source has been exhausted.
 *
 * As bytes are returned from upstream they are written to a local file. Downstream sources read
 * from this file as necessary.
 *

   * and response body streams; otherwise resources may be leaked.
   *
   * This method is safe to be called concurrently, but provides limited guarantees. If a transport
   * layer connection has been established (such as a HTTP/2 stream) that is terminated. Otherwise
   * if a socket connection is being established, that is terminated.
   */
  override fun cancel() {
    if (canceled) return // Already canceled.

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.
  MockWebServer server = new MockWebServer();

  // Schedule some responses.
  server.enqueue(new MockResponse().setBody("hello, world!"));

    return writer
  }

  /**
   * Shortens the last frame from its original length to `length`. This will cause the peer to
   * close the socket as soon as this frame has been written; otherwise the peer stays open until
   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {
    val lastFrame = outFrames.removeAt(outFrames.size - 1)

    HTTP/2 to 16 MiB of unacknowledged data per connection. With this fix there is a limit of 16 MiB
    of unacknowledged data per stream and no per-connection limit.

 *  Fix: Don't operate on a connection after it's been returned to the pool. This race occurred
    on failed web socket connection attempts.

 *  Upgrade: [Okio 3.6.0][okio_3_6_0].

 *  Upgrade: [Kotlin 1.8.21][kotlin_1_8_21].


## Version 4.11.0

_2023-04-22_

    assertThat(server.requestCount).isEqualTo(2)
  }

  @Test
  fun readTimeouts() {
    // This relies on the fact that MockWebServer doesn't close the
    // connection after a response has been sent. This causes the client to
    // try to read more bytes than are sent, which results in a timeout.
    server.enqueue(
      MockResponse.Builder()
        .body("ABC")
        .clearHeaders()

    assertInvalid("http://[::1%2544]", "Invalid URL host: \"[::1%2544]\"")
  }

  @Test
  fun hostIpv6AddressTooManyLeadingZeros() {
    // Guava's been buggy on this case. https://github.com/google/guava/issues/3116
    assertInvalid(
      "http://[2001:db8:0:0:1:0:0:00001]",
      "Invalid URL host: \"[2001:db8:0:0:1:0:0:00001]\"",
    )
  }

  @Test

 *
 *  * **Connecting:** the initial state of each web socket. Messages may be enqueued but they won't
 *    be transmitted until the web socket is open.
 *
 *  * **Open:** the web socket has been accepted by the remote peer and is fully operational.
 *    Messages in either direction are enqueued for immediate transmission.
 *
 *  * **Closing:** one of the peers on the web socket has initiated a graceful shutdown. The web

 * Note that an allocation may be released before its stream is completed. This is intended to make
 * bookkeeping easier for the caller: releasing the allocation as soon as the terminal stream has
 * been found. But only complete the stream once its data stream has been exhausted.
 */
interface Connection {
  /** Returns the route used by this connection. */
  fun route(): Route

  /**
   * Returns the socket that this connection is using. Returns an