* both.
 *
 * Applications may configure OkHttp with an authenticator for origin servers, or proxy servers,
 * or both.
 *
 * ## Authentication Retries
 *
 * If your authentication may be flaky and requires retries you should apply some policy
 * to limit the retries by the class of errors and number of attempts.  To get the number of
 * attempts to the current point use this function.
 *
 * ```java

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

### Events with Retries and Follow-Ups

OkHttp is resilient and can automatically recover from some connectivity failures. In this case, the `connectFailed()` event is not terminal and not followed by `callFailed()`. Event listeners will receive multiple events of the same type when retries are attempted.

assertEquals("application/json; charset=utf-8", request.getHeader("Content-Type"));
assertEquals("{}", request.getBody().readUtf8());
```

#### Dispatcher

By default MockWebServer uses a queue to specify a series of responses. Use a
Dispatcher (`import okhttp3.mockwebserver.Dispatcher`) to handle requests using another policy. One natural policy is to
dispatch on the request path.

**This release fixes a severe bug where OkHttp incorrectly detected and recovered from unhealthy
connections.** Stale or canceled connections were incorrectly attempted when they shouldn't have
been, leading to rare cases of infinite retries. Please upgrade to this release!

 *  Fix: don't return stale DNS entries in `DnsOverHttps`. We were caching DNS results indefinitely
    rather than the duration specified in the response's cache-control header.

 * for a call. In future releases of OkHttp these events may also occur concurrently to permit
 * multiple routes to be attempted simultaneously.
 *
 * Events and sequences of events may be repeated for retries and follow-ups.
 *
 * All event methods must execute fast, without external locking, cannot throw exceptions, attempt
 * to mutate the event parameters, or be re-entrant back into the client. Any IO - writing to files

  /**
   * Cancel this stream. Resources held by this stream will be cleaned up, though not synchronously.
   * That may happen later by the connection pool thread.
   */
  fun cancel()

  /**
   * Carries an exchange. This is usually a connection, but it could also be a connect plan for
   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.
   */
  interface Carrier {
    val route: Route

      fun run() {
        val request = Request.Builder()
            .url("http://publicobject.com/secrets/hellosecret.txt")
            .build()
      }
    ```

    To avoid making many retries when authentication isn't working, you can return null to give up. For example, you may want to skip the retry when these exact credentials have already been attempted:

    ```kotlin

// Rad Web Hosting: https://radwebhosting.com
// Submitted by Scott Claeys <******@****.***>
cloudsite.builders

// Redgate Software: https://red-gate.com
// Submitted by Andrew Farries <andrew.farries@red-gate.com>
instances.spawn.cc

// Redstar Consultants : https://www.redstarconsultants.com/
// Submitted by Jons Slemmer <******@****.***>
instantcloud.cn

   * [WindowCounter] generally carries the client view of total and acked bytes.
   */
  fun receivingStreamWindowChanged(
    streamId: Int,
    windowCounter: WindowCounter,
    bufferSize: Long,
  )

  /**
   * Notification that the receiving connection flow control window has changed.
   * [WindowCounter] generally carries the client view of total and acked bytes.
   */

 * **Exchange** carries a single HTTP request/response pair.

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.