**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.

      apply {
        this.socketPolicy = socketPolicy
      }

    /**
     * Throttles the request reader and response writer to sleep for the given period after each
     * series of [bytesPerPeriod] bytes are transferred. Use this to simulate network behavior.
     */
    fun throttleBody(
      bytesPerPeriod: Long,
      period: Long,
      unit: TimeUnit,
    ) = apply {

   *
   * https://github.com/square/okhttp/pull/7190
   */
  @Test
  fun preferCallConnectionOverDeferredConnection() {
    // Make sure we have enough connection options to permit retries.
    dnsResults =
      listOf(
        localhostIpv4,
        localhostIpv6,
        TestUtil.UNREACHABLE_ADDRESS_IPV4.address,
      )
    serverIpv4.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)

   * sent.
   */
  private fun recover(
    e: IOException,
    call: RealCall,
    userRequest: Request,
    requestSendStarted: Boolean,
  ): Boolean {
    // The application layer has forbidden retries.
    if (!client.retryOnConnectionFailure) return false

    // We can't send the request body again.
    if (requestSendStarted && requestIsOneShot(e, userRequest)) return false

    // This exception is fatal.

    val PARALLEL = "multipart/parallel".toMediaType()

    /**
     * The media-type multipart/form-data follows the rules of all multipart MIME data streams as
     * outlined in RFC 2046. In forms, there are a series of fields to be supplied by the user who
     * fills out the form. Each field has a name. Within a given form, the names are unique.
     */
    @JvmField
    val FORM = "multipart/form-data".toMediaType()

additional improvements for Kotlin users. In this alpha we're excited to skip-the-builder for
requests and remove a common source of non-null assertions (`!!`) on the response body.

The alpha releases in the 5.0.0 series have production-quality code and an unstable API. We expect
to make changes to the APIs introduced in 5.0.0-alpha.X. These releases are safe for production use

## Version 2.1.0

_2014-11-11_

 *  New: Typesafe APIs for interacting with cipher suites and TLS versions.
 *  Fix: Don't crash when mixing authorization challenges with upload retries.


## Version 2.1.0-RC1

_2014-11-04_

 *  **OkHttp now caches private responses**. We've changed from a shared cache
    to a private cache, and will now store responses that use an `Authorization`

 * 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

      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