* [duplex calls][RequestBody.isDuplex] interleave the request and response bodies.
 *
 * Since connections may be reused, the proxy selection, DNS, and connect events may not be present
 * 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.

      .assertRequestHeader("Accept-Language") // No Vary on Accept-Language.
      .assertRequestHeader("Accept-Charset", "UTF-8") // Because of Vary on Accept-Charset.
      .assertRequestHeader("If-None-Match") // This wasn't present in the original request.
      .assertSentRequestAtMillis(request1SentAt, request1ReceivedAt)
      .assertReceivedResponseAtMillis(request1SentAt, request1ReceivedAt)

import java.util.logging.SimpleFormatter
import kotlin.reflect.KClass
import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.http2.Http2

object OkHttpDebugLogging {
  // Keep references to loggers to prevent their configuration from being GC'd.
  private val configuredLoggers = CopyOnWriteArraySet<Logger>()

  fun enableHttp2() = enable(Http2::class)

  fun enableTaskRunner() = enable(TaskRunner::class)

 *
 * Canceling a task that is waiting to execute prevents that upcoming execution. Canceling a task
 * that is currently executing does not impact the ongoing run, but it does prevent a recurrence
 * from being scheduled.
 *
 * Tasks may opt-out of cancellation with `cancelable = false`. Such tasks will recur until they
 * decide not to by returning -1L.
 *
 * Task Queues
 * -----------
 *

import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.internal.SuppressSignatureCheck
import okhttp3.internal.platform.Platform

/**
 * Example of using a hardware key to perform client auth.
 * Prefer recent JDK builds, and results are temperamental to slight environment changes.
 * Different instructions and configuration may be required for other hardware devices.
 *
 * Using a yubikey device as a SSL key store.

  }

  @Flaky
  @RetryingTest(5)
  fun missingClientAuthFailsForNeeds() {
    // Fails with 11.0.1 https://github.com/square/okhttp/issues/4598
    // StreamReset stream was reset: PROT...
    val client = buildClient(null, clientIntermediateCa.certificate)
    val socketFactory = buildServerSslSocketFactory()
    server.useHttps(socketFactory)
    server.requireClientAuth()

The connection lock is never held while doing I/O (even closing a socket) to prevent contention.

      val clientCertificates =
        HandshakeCertificates.Builder()
          .addPlatformTrustedCertificates()
          .addInsecureHost(server.hostName)
          .build()

      // Need fresh client to reset sslSocketFactoryOrNull
      client =
        OkHttpClient.Builder()
          .eventListenerFactory(
            clientTestRule.wrap(
              object : EventListener() {

    // Check that we do indeed have more than one route.
    assertThat(regularRoutes.size).isEqualTo(numberOfAddresses)
    // Add first regular route as failed.
    routeDatabase.failed(regularRoutes[0])
    // Reset selector
    routeSelector = newRouteSelector(address)

    // The first selection prioritizes the non-failed routes.
    val selection2 = routeSelector.next()
    assertThat(selection2.next()).isEqualTo(regularRoutes[1])

    // The in-flight editor can still write after a trim failure.
    inFlightEditor.setString(0, "cc")
    inFlightEditor.setString(1, "cc")
    inFlightEditor.commit()

    // Confirm the committed values are present after a successful cache trim.
    filesystem.setFaultyDelete(cacheDir / "a.0", false)
    taskFaker.runNextTask()
    assertValue("c", "cc", "cc")
  }

  @ParameterizedTest