## Version 3.12.0

_2018-11-16_

 *  **OkHttp now supports TLS 1.3.** This requires either Conscrypt or Java 11+.

 *  **Proxy authenticators are now asked for preemptive authentication.** OkHttp will now request
    authentication credentials before creating TLS tunnels through HTTP proxies (HTTP `CONNECT`).

    return such malformed responses will now trigger a `ProtocolException` in
    the client.

 *  **WebSocketListener has incompatible changes.** The `onOpen()` method is now
    called on the reader thread, so implementations must return before further
    websocket messages will be delivered. The `onFailure()` method now includes
    an HTTP response if one was returned.

## Version 2.4.0-RC1

* sysctl support is now considered beta ([ref](https://github.com/kubernetes/enhancements/issues/34))
* Support for Azure Virtual Machine Scale Sets is now considered beta. ([ref](https://github.com/kubernetes/enhancements/issues/513))
* Azure support for Cluster Autoscaler is now considered beta. ([ref](https://github.com/kubernetes/enhancements/issues/514))

## Other Asynchronous Function Calls

As the testing function is now asynchronous, you can now also call (and `await`) other `async` functions apart from sending requests to your FastAPI application in your tests, exactly as you would call them anywhere else in your code.

!!! tip

    But it's provided here to be compliant with the specifications.

    Also, there might be tools that expect and use it (now or in the future) and that might be useful for you or your users, now or in the future.

    That's the benefit of standards...

## See it in action

 *  Add a media type class to OkHttp.
 *  Change custom header prefix:

    ```
    X-Android-Sent-Millis is now OkHttp-Sent-Millis
    X-Android-Received-Millis is now OkHttp-Received-Millis
    X-Android-Response-Source is now OkHttp-Response-Source
    X-Android-Selected-Transport is now OkHttp-Selected-Transport
    ```
 *  Improve cache invalidation for POST-like requests.

        val candidateDelay = maxOf(0L, candidate.nextExecuteNanoTime - now)

        when {
          // Compute the delay of the soonest-executable task.
          candidateDelay > 0L -> {
            minDelayNanos = minOf(candidateDelay, minDelayNanos)
            continue@eachQueue
          }

          // If we already have more than one task, that's enough work for now. Stop searching.
          readyTask != null -> {

- Kubeadm init phase certs now support the `--csr-only` option, simplifying custom CA creation.
- `kubeadm join --experimental-control-plane` now automatically adds a new etcd member for `local etcd` mode, further simplifying required tasks for HA clusters setup.

*   <THIS SECTION SHOULD CONTAIN API, ABI AND BEHAVIORAL BREAKING CHANGES>

*   `tf.summary.trace_on` now takes a `profiler_outdir` argument. This must be
    set if `profiler` arg is set to `True`.

    *   `tf.summary.trace_export`'s `profiler_outdir` arg is now a no-op.
        Enabling the profiler now requires setting `profiler_outdir` in
        `trace_on`.

*   `tf.estimator`

### Create a *path operation* to test it

Now, to be able to test that everything works, create a *path operation*:

```Python hl_lines="36-38"
{!../../../docs_src/custom_docs_ui/tutorial001.py!}
```

### Test it