@Override
          public void onSuccess(String result) {
            fail("Was not expecting onSuccess() to be called.");
          }

          @Override
          public void onFailure(Throwable t) {
            synchronized (monitor) {
              assertFalse(called);
              assertThat(t).isInstanceOf(CancellationException.class);
              called = true;
            }
          }

          @Override
          public void onSuccess(String result) {
            fail("Was not expecting onSuccess() to be called.");
          }

          @Override
          public void onFailure(Throwable t) {
            synchronized (monitor) {
              assertFalse(called);
              assertThat(t).isInstanceOf(CancellationException.class);
              called = true;
            }
          }

      events.add(Closed(code, reason))
    }
  }

  override fun onFailure(
    webSocket: WebSocket,
    t: Throwable,
    response: Response?,
  ) {
    Platform.get().log("[WS $name] onFailure", Platform.INFO, t)
    val delegate = delegate
    if (delegate != null) {
      this.delegate = null
      delegate.onFailure(webSocket, t, response)
    } else {
      events.add(Failure(t, response))
    }

    f.addCallback(
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            called[0] = true;
          }

          @Override
          public void onFailure(Throwable t) {}
        },
        directExecutor());
    assertThat(called[0]).isTrue();
  }

  // Avoid trouble with automatic mapping between JRE and Kotlin runtime classes.

    f.addCallback(
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            called[0] = true;
          }

          @Override
          public void onFailure(Throwable t) {}
        },
        directExecutor());
    assertThat(called[0]).isTrue();
  }

  // Avoid trouble with automatic mapping between JRE and Kotlin runtime classes.

    clientListener.setNextEventDelegate(
      object : WebSocketListener() {
        override fun onFailure(
          webSocket: WebSocket,
          t: Throwable,
          response: Response?,
        ): Unit = throw e
      },
    )
    newWebSocket()
    assertThat(testLogHandler.take()).isEqualTo("INFO: [WS client] onFailure")
  }

  @Test
  fun throwingOnMessageClosesImmediatelyAndFails() {

    val call =
      client.newCall(
        Request
          .Builder()
          .url(server.url("/"))
          .build(),
      )
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: okio.IOException,
        ) {
          callFailure.complete(e)
        }

        override fun onResponse(
          call: Call,
          response: Response,

        .url(url)
        .build()

    val promise = CompletableFuture<Response>()

    val call = client.newCall(request)
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          promise.completeExceptionally(e)
        }

        override fun onResponse(
          call: Call,
          response: Response,

        ): T = TODO()

        override fun clone(): Call = TODO()
      }
  }

  @Test
  fun callback() {
    val callback =
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) = TODO()

        override fun onResponse(
          call: Call,
          response: Response,
        ) = TODO()
      }
  }

    requestCanceledLatch: CountDownLatch?,
  ) {
    val call = client.newCall(Request(server.url("/")))
    val latch = CountDownLatch(1)
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          latch.countDown()
        }

        override fun onResponse(
          call: Call,
          response: Response,