}
    body.awaitSuccess()
  }

  /**
   * Duplex calls that have follow-ups are weird. By the time we know there's a follow-up we've
   * already split off another thread to stream the request body. Because we permit at most one
   * exchange at a time we break the request stream out from under that writer.
   */
  @Test
  fun duplexWithRedirect() {
    enableProtocol(Protocol.HTTP_2)

    val b1 = source.readByte() and 0xff

    val isMasked = b1 and B1_FLAG_MASK != 0
    if (isMasked == isClient) {
      // Masked payloads must be read on the server. Unmasked payloads must be read on the client.
      throw ProtocolException(
        if (isClient) {
          "Server-sent frames must not be masked."
        } else {
          "Client-sent frames must be masked."

    // A conditional cache hit updates the cache.
    Thread.sleep(500) // Make sure t0 and t1 are distinct.
    val t1 = System.currentTimeMillis()
    val response2 = get(server.url("/a"))
    assertThat(response2.code).isEqualTo(HttpURLConnection.HTTP_OK)
    assertThat(response2.body.string()).isEqualTo("A")
    assertThat(response2.header("Allow")).isEqualTo("GET, HEAD")
    val updatedTimestamp = response2.receivedResponseAtMillis

  private fun sleep(delayMillis: Int) {
    try {
      Thread.sleep(delayMillis.toLong())
    } catch (e: InterruptedException) {
      Thread.currentThread().interrupt()
    }
  }

  private fun cancelLater(
    call: Call,
    delayMillis: Int,
  ): CountDownLatch {
    val latch = CountDownLatch(1)
    Thread {
      sleep(delayMillis)
      if (cancelMode == CANCEL) {

    // Enqueueing the red task starts a thread because the head of the queue changed.
    redQueue.execute("red task") {
      log += "red:starting@${taskFaker.nanoTime}"
      taskFaker.sleep(100.µs)
      log += "red:finishing@${taskFaker.nanoTime}"
    }
    assertThat(taskFaker.executeCallCount).isEqualTo(1)

    // Enqueueing the blue task doesn't start a thread because the red one is still starting.

        .build()
    val request = Request(server.url("/"))
    val response1 = client.newCall(request).execute()
    assertThat(response1.body.string()).isEqualTo("a")

    // Give the thread pool a chance to evict.
    Thread.sleep(500)
    val response2 = client.newCall(request).execute()
    assertThat(response2.body.string()).isEqualTo("b")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

  @Throws(IOException::class)
  fun trailers(): Headers

  /**
   * Cancel this stream. Resources held by this stream will be cleaned up, though not synchronously.
   * That may happen later by the connection pool thread.
   */
  fun cancel()

  /**
   * Carries an exchange. This is usually a connection, but it could also be a connect plan for
   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.

    assertThat(inputStream!!.read()).isEqualTo('A'.code)
    assertThat(inputStream.read()).isEqualTo('B'.code)
    assertThat(inputStream.read()).isEqualTo('C'.code)
    assertThat(inputStream.read()).isEqualTo('D'.code)
    assertThat(inputStream.read()).isEqualTo('E'.code)
    assertThat(inputStream.read()).isEqualTo('F'.code)
    assertThat(inputStream.read()).isEqualTo(-1)

    }
  }

  @Test fun threadIsInterruptedOnFirstRead() {
    Thread.currentThread().interrupt()
    try {
      val result = publicSuffixDatabase.getEffectiveTldPlusOne("squareup.com")
      assertThat(result).isEqualTo("squareup.com")
    } finally {
      assertThat(Thread.interrupted()).isTrue()
    }
  }

  @Test fun secondReadFailsSameAsFirst() {

      return failFastResponse!!
    }

    val result = responseQueue.take()

    // If take() returned because we're shutting down, then enqueue another dead letter so that any
    // other threads waiting on take() will also return.
    if (result == DEAD_LETTER) responseQueue.add(DEAD_LETTER)

    return result
  }

  override fun peek(): MockResponse {