* server's hostname is sent to the proxy.
 *
 * Prior to sending any CONNECT request OkHttp always calls the proxy authenticator so that it may
 * prepare preemptive authentication. OkHttp will call [authenticate] with a fake `HTTP/1.1 407
 * Proxy Authentication Required` response that has a `Proxy-Authenticate: OkHttp-Preemptive`

        .url(server.url("/"))
        .post(AsyncRequestBody())
        .build()
    val call = client.newCall(request)
    call.timeout().timeout(250, TimeUnit.MILLISECONDS)
    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("timeout")
      assertTrue(call.isCanceled())
    }
  }

  @Test
  fun fullCallTimeoutDoesNotApplyOnceConnected() {

    // TODO: test whether null is supported (create a Feature)
    /**
     * The elements to be returned by future calls to {@code next()}, with the first at the top of
     * the stack.
     */
    final Stack<E> nextElements = new Stack<>();

    /**
     * The elements to be returned by future calls to {@code previous()}, with the first at the top
     * of the stack.
     */

  // +optional
  optional string sideEffects = 6;

  // TimeoutSeconds specifies the timeout for this webhook. After the timeout passes,
  // the webhook call will be ignored or the API call will fail based on the
  // failure policy.
  // The timeout value must be between 1 and 30 seconds.
  // Default to 30 seconds.
  // +optional
  optional int32 timeoutSeconds = 7;

The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

    // Output status
    TF_Status*);

// Set up the graph with the intended feeds (inputs) and fetches (outputs) for a
// sequence of partial run calls.
//
// On success, returns a handle that is used for subsequent PRun calls. The
// handle should be deleted with TF_DeletePRunHandle when it is no longer
// needed.
//
// On failure, out_status contains a tensorflow::Status with an error

        .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)

    // unless it's actually going to be used; validate() is called for all set method calls, so it
    // needs to be fast.
    // (We could instead generate the message once, when the set is created, but zero is better.)
    if (!validator.get()) {
      throw new IllegalStateException(errorMessage.get());
    }
  }

     *
     * - If the stack overflowed before set()/setValue() could even store the result in the output
     * Future, then a call setException() would likely also overflow.
     *
     * - If the stack overflowed after set()/setValue() stored its result, then a call to
     * setException() will be a no-op because the Future is already done.
     *

   * listeners are added before any of the managed services are {@linkplain Service#startAsync
   * started}.
   *
   * <p>{@code addListener} guarantees execution ordering across calls to a given listener but not
   * across calls to multiple listeners. Specifically, a given listener will have its callbacks
   * invoked in the same order as the underlying service enters those states. Additionally, at most