route: Route?,
            response: Response,
          ): Request? {
            if (response.request.header("Authorization") != null) {
              return null // Give up, we've already attempted to authenticate.
            }

            println("Authenticating for response: $response")
            println("Challenges: ${response.challenges()}")
            val credential = Credentials.basic("jesse", "password1")

 * or to force a specific known IP address.
 *
 * Implementations of this interface must be safe for concurrent use.
 */
fun interface Dns {
  /**
   * Returns the IP addresses of `hostname`, in the order they will be attempted by OkHttp. If a
   * connection to an address fails, OkHttp will retry the connection with the next address until
   * either a connection is made, the set of IP addresses is exhausted, or a limit is exceeded.
   */

        connectionPool.scheduleCloser()
      }
    }
  }

  override fun handshake(): Handshake? = handshake

  /** Track a bad route in the route database. Other routes will be attempted first. */
  internal fun connectFailed(
    client: OkHttpClient,
    failedRoute: Route,
    failure: IOException,
  ) {
    // Tell the proxy selector when we fail to connect on a fresh connection.

          return null
        }
        val priorResponse = userResponse.priorResponse
        if (priorResponse != null && priorResponse.code == HTTP_CLIENT_TIMEOUT) {
          // We attempted to retry and got another timeout. Give up.
          return null
        }

        if (retryAfter(userResponse, 0) > 0) {
          return null
        }

        return userResponse.request
      }

  }

  /**
   * Invoked immediately after a TLS connection was attempted.
   *
   * This method is invoked after [secureConnectStart].
   */
  open fun secureConnectEnd(
    call: Call,
    handshake: Handshake?,
  ) {
  }

  /**
   * Invoked immediately after a socket connection was attempted.
   *

## Version 4.5.0

_2020-04-06_

**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

    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->
      assertThat(expected).hasMessage("timeout")
    }
  }

  /**
   * This test reproduces a crash where OkHttp attempted to use a deferred connection when the call
   * already had a healthy connection. It sets up a deferred connection by stalling the IPv6
   * connect, and it sets up a same-connection retry with [ErrorCode.REFUSED_STREAM].
   *

   * proxy server can issue an auth challenge and then close the connection.
   *
   * @return the next plan to attempt, or null if no further attempt should be made either because
   *     we've successfully connected or because no further attempts should be made.
   */
  @Throws(IOException::class)
  internal fun connectTunnel(): ConnectResult {
    val nextTunnelRequest =
      createTunnel()

internal fun Socket.peerName(): String {
  val address = remoteSocketAddress
  return if (address is InetSocketAddress) address.hostName else address.toString()
}

/**
 * Returns true if new reads and writes should be attempted on this.
 *
 * Unfortunately Java's networking APIs don't offer a good health check, so we go on our own by
 * attempting to read with a short timeout. If the fails immediately we know the socket is
 * unhealthy.
 *

    // We know that a fresh connection was created if the server recorded a request with sequence
    // number 0. Since the client may have attempted to reuse the broken connection just before
    // creating a fresh connection, the server may have recorded 2 requests at this point. The order
    // of recording is non-deterministic.
    val requestAfter = server.takeRequest()