**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.

    }
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0) // New connection.

    // Second call attempts the pooled connection, and it fails. Then it retries a new route which
    // succeeds.
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("abc")

   * 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.

     *
     * The call timeout spans the entire call: resolving DNS, connecting, writing the request body,
     * server processing, and reading the response body. If the call requires redirects or retries
     * all must complete within one timeout period.
     *
     * The default value is 0 which imposes no timeout.
     */
    fun callTimeout(
      timeout: Long,
      unit: TimeUnit,

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