assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Note that although we have two routes available, we only use one. The retry is permitted
    // because there are routes available, but it chooses the existing connection since it isn't
    // yet considered unhealthy.
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(1)
  }

  @ParameterizedTest
  @ArgumentsSource(ProtocolParamProvider::class)

 *     failed connect attempts (such as trying the next [ConnectionSpec]), or as attempts that lost
 *     a race in fast follow-up.
 *
 *  4. If there's no existing connection, make a list of routes (which may require blocking DNS
 *     lookups) and attempt a new connection them. When failures occur, retries iterate the list of
 *     available routes.
 *

  }

  internal fun enqueue(call: AsyncCall) {
    this.withLock {
      readyAsyncCalls.add(call)

      // Mutate the AsyncCall so that it shares the AtomicInteger of an existing running call to
      // the same host.
      if (!call.call.forWebSocket) {
        val existingCall = findExistingCallWithHost(call.host)
        if (existingCall != null) call.reuseCallsPerHostFrom(existingCall)

    val localNextRouteToTry = nextRouteToTry
    if (localNextRouteToTry != null) {
      nextRouteToTry = null
      return planConnectToRoute(localNextRouteToTry)
    }

    // Use a route from an existing route selection.
    val existingRouteSelection = routeSelection
    if (existingRouteSelection != null && existingRouteSelection.hasNext()) {
      return planConnectToRoute(existingRouteSelection.next())
    }

  @Throws(IOException::class)
  fun flush() {
    writer.flush()
  }

  /**
   * Degrades this connection such that new streams can neither be created locally, nor accepted
   * from the remote peer. Existing streams are not impacted. This is intended to permit an endpoint
   * to gracefully stop accepting new requests without harming previously established streams.
   */
  @Throws(IOException::class)

 *  New: `Cache` now has a public constructor that takes an [okio.FileSystem]. This should make it
    possible to implement decorators for cache encryption or compression.
 *  New: `Cookie.newBuilder()` to build upon an existing cookie.
 *  New: Use TLSv1.3 when running on JDK 8u261 or newer.
 *  New: `QueueDispatcher.clear()` may be used to reset a MockWebServer instance.

   *
   * This can be invoked more than 1 time for a single [Call]. For example, if the response to the
   * [Call.request] is a redirect to a different host.
   *
   * If the [Call] is able to reuse an existing pooled connection, this method will not be invoked.
   * See [ConnectionPool].
   */
  open fun dnsStart(
    call: Call,
    domainName: String,
  ) {
  }

  /**

    assertEquals(0, client.connectionPool.connectionCount())

    // Force reuse. This appears flaky (30% of the time) even though sessions are reused.
    // javax.net.ssl.SSLHandshakeException: No new session is allowed and no existing
    // session can be resumed
    //
    // Report https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8264944
    // Sessions improvement https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8245576

 *
 * Copy WireSharkKeyLoggerListener to your test code to use in development.
 *
 * This logs TLSv1.2 on a JVM (OpenJDK 11+) without any additional code.  For TLSv1.3
 * an existing external tool is required.
 *
 * See https://stackoverflow.com/questions/61929216/how-to-log-tlsv1-3-keys-in-jsse-for-wireshark-to-decode-traffic
 *
 * Steps to run in your own code
 *

      if (state.address != connection.route.address) continue
      connection.withLock {
        concurrentCallCapacity += connection.allocationLimit
      }

      // The policy was satisfied by existing connections, don't run again
      if (concurrentCallCapacity >= state.policy.minimumConcurrentCalls) return -1L
    }

    // If we got here then the policy was not satisfied -- open a connection!
    try {