* find an exchange to carry the request.
   *
   * Note that an exchange will not be needed if the request is satisfied by the cache.
   *
   * @param newRoutePlanner true if this is not a retry and new routing can be performed.
   */
  fun enterNetworkInterceptorExchange(
    request: Request,
    newRoutePlanner: Boolean,
    chain: RealInterceptorChain,
  ) {

    }
    ```

 *  New: Upgrade to Okio 2.4.3.

    ```kotlin
    implementation("com.squareup.okio:okio:2.4.3")
    ```

 *  Fix: Limit retry attempts for HTTP/2 `REFUSED_STREAM` and `CANCEL` failures.
 *  Fix: Retry automatically when incorrectly sharing a connection among multiple hostnames. OkHttp
    shares connections when hosts share both IP addresses and certificates, such as `squareup.com`

  fun metadata(): ByteString = metadata

  /**
   * Returns a new source that returns the same bytes as upstream. Returns null if this relay has
   * been closed and no further sources are possible. In that case callers should retry after
   * building a new relay with [.read].
   */
  fun newSource(): Source? {
    synchronized(this@Relay) {
      if (file == null) return null
      sourceCount++
    }

    return RelaySource()

 *    we must send a `CONNECT` request, and handle authorization challenges from the proxy.
 *  * Optional [TLS handshake][connectTls].
 *
 * Each step may fail. If a retry is possible, a new instance is created with the next plan, which
 * will be configured differently.
 */
class ConnectPlan(
  private val taskRunner: TaskRunner,
  private val connectionPool: RealConnectionPool,

  /**
   * Returns the response for the HTTP redirect or authorization challenge that triggered this
   * response, or null if this response wasn't triggered by an automatic retry. The body of the
   * returned response should not be read because it has already been consumed by the redirecting
   * client.
   */
  @get:JvmName("priorResponse") val priorResponse: Response?,
  /**

    // Set up a same-connection retry.
    serverIpv4.enqueue(
      MockResponse(socketPolicy = ResetStreamAtStart(ErrorCode.REFUSED_STREAM.httpCode)),
    )
    serverIpv4.enqueue(
      MockResponse(body = "this was the 2nd request on IPv4"),
    )
    serverIpv6.enqueue(
      MockResponse(body = "unexpected call to IPv6"),
    )

    // Confirm the retry succeeds on the same connection.

      // If the problem was a CertificateException from the X509TrustManager,
      // do not retry.
      if (e.cause is CertificateException) {
        return false
      }
    }
    if (e is SSLPeerUnverifiedException) {
      // e.g. a certificate pinning error.
      return false
    }
    // An example of one we might want to retry with a different route is a problem connecting to a

    running SSLv3, you must manually configure your own `ConnectionSpec`.

 *  **OkHttp now offers interceptors.** Interceptors are a powerful mechanism
    that can monitor, rewrite, and retry calls. The [interceptors doc][interceptors] is a full
    introduction to this new API.

 *  New: APIs to iterate and selectively clear the response cache.
 *  New: Support for SOCKS proxies.

      // the journal rebuild failed, the journal writer will not be active, meaning we will not be
      // able to record the edit, causing file leaks. In both cases, we want to retry the clean up
      // so we can get out of this state!
      cleanupQueue.schedule(cleanupTask)
      return null
    }

    // Flush the journal before creating files to prevent file leaks.

    ```kotlin
    if (credential == response.request.header("Authorization")) {
      return null // If we already failed with these credentials, don't retry.
     }
    ```

    You may also skip the retry when you’ve hit an application-defined attempt limit:

    ```kotlin