localhostIpv4,
        localhostIpv6,
      )
    serverIpv4.enqueue(
      MockResponse(body = "unexpected call to IPv4"),
    )
    serverIpv6.enqueue(
      MockResponse(body = "hello from IPv6"),
    )

    val call = client.newCall(Request(url))
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("hello from IPv6")

    check(exchange == null) { "Timeouts can't be adjusted in a network interceptor" }

    return copy(writeTimeoutMillis = checkDuration("writeTimeout", timeout.toLong(), unit))
  }

  override fun call(): Call = call

  override fun request(): Request = request

  @Throws(IOException::class)
  override fun proceed(request: Request): Response {
    check(index < interceptors.size)

    calls++

        .build()
    val call = client.newCall(request1)
    assertFailsWith<SocketTimeoutException> {
      call.execute() // we want this call to throw a SocketTimeoutException
    }
  }

  @Test
  fun chainCanCancelCall() {
    val callRef = AtomicReference<Call>()
    val interceptor =
      Interceptor { chain: Interceptor.Chain ->
        val call = chain.call()
        callRef.set(call)

    serverRule.server.enqueue(MockResponse())

    val call = client.newCall(Request(serverRule.server.url("/")))

    call.execute().use { response ->
      assertThat(response.code).isEqualTo(200)
    }
  }

  @Test
  fun testRequestExternal() {
    assumeNetwork()

    val call = client.newCall(Request("https://google.com/robots.txt".toHttpUrl()))

    call.execute().use { response ->

 * [close()][Response.close] for you.
 *
 * ```java
 * Call call = client.newCall(request);
 * try (Response response = call.execute()) {
 * ... // Use the response.
 * }
 * ```
 *
 * You can use a similar block for asynchronous calls:
 *
 * ```java
 * Call call = client.newCall(request);
 * call.enqueue(new Callback() {
 *   public void onResponse(Call call, Response response) throws IOException {

class CacheInterceptor(internal val cache: Cache?) : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {
    val call = chain.call()
    val cacheCandidate = cache?.get(chain.request().requestForCache())

    val now = System.currentTimeMillis()

    val strategy = CacheStrategy.Factory(now, chain.request(), cacheCandidate).compute()

    val client =
      OkHttpClient.Builder()
        .connectionPool(poolApi)
        .build()
    val call = client.newCall(Request(addressA.url)) as RealCall
    call.enterNetworkInterceptorExchange(call.request(), true, factory.newChain(call))
    c1.withLock { call.acquireConnectionNoEvents(c1) }

    // Running at time 50, the pool returns that nothing can be evicted until time 150.

_2019-09-29_

 *  Fix: Cancel calls that fail due to unexpected exceptions. We had a bug where an enqueued call
    would never call back if it crashed with an unchecked throwable, such as a
    `NullPointerException` or `OutOfMemoryError`. We now call `Callback.onFailure()` with an
    `IOException` that reports the call as canceled. The triggering exception is still delivered to
    the thread's `UncaughtExceptionHandler`.

  }

  fun finishJob(url: String) {
    val i = calls.iterator()
    while (i.hasNext()) {
      val call = i.next()
      if (call.request.url.toString() == url) {
        i.remove()
        dispatcherTest.dispatcher.finishedAccessor(call)
        return
      }
    }
    throw AssertionError("No such job: $url")
  }

  override fun shutdown() {
    shutdown = true
  }

## [Calls](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-call/)