* on what they know about the particular Joiner instances the calls are performed on.
     *
     * (In addition to useForNull, we also offer skipNulls. It, too, tolerates null inputs, but its
     * tolerance is implemented differently: Its implementation avoids calling this toString(Object)
     * method in the first place.)
     */
    requireNonNull(part);

_2025-07-02_

This is our first stable release of OkHttp since 2023. Here's the highlights if you're upgrading
from OkHttp 4.x:

**OkHttp is now packaged as separate JVM and Android artifacts.** This allows us to offer
platform-specific features and optimizations. If your build system handles [Gradle module metadata],
this change should be automatic.

    client = TestClient(mod.app)
    return client


def test_post_all(client: TestClient):
    data = {
        "name": "Special Offer",
        "description": "This is a special offer",
        "price": 38.6,
        "items": [
            {
                "name": "Foo",
                "description": "A very nice Item",
                "price": 35.4,

     * outperform {@code LinkedList} except in certain rare and specific situations. Unless you have
     * spent a lot of time benchmarking your specific needs, use one of those instead. (However, we
     * do not currently offer a {@link Multimap} implementation based on {@link
     * java.util.ArrayDeque}.)
     */
    public ListMultimapBuilder<K0, @Nullable Object> linkedListValues() {
      return new ListMultimapBuilder<K0, @Nullable Object>() {

     * outperform {@code LinkedList} except in certain rare and specific situations. Unless you have
     * spent a lot of time benchmarking your specific needs, use one of those instead. (However, we
     * do not currently offer a {@link Multimap} implementation based on {@link
     * java.util.ArrayDeque}.)
     */
    public ListMultimapBuilder<K0, @Nullable Object> linkedListValues() {
      return new ListMultimapBuilder<K0, @Nullable Object>() {

 * `Function<@Nullable A, @Nullable B>` already had to find a workaround. Still, there is a *ton* of
 * fallout from trying to switch. I would be shocked if the switch would offer benefits to anywhere
 * near enough users to justify the costs.
 *
 * Fortunately, if anyone does want to use a Converter as a `Function<@Nullable A, @Nullable B>`,
 * it's easy to get one: `converter::convert`.
 *

_2020-03-17_

**This release candidate turns on web socket compression.**

The [spec][rfc_7692] includes a sophisticated mechanism for client and server to negotiate
compression features. We strive to offer great performance in our default configuration and so we're
making compression the default for everyone starting with this release candidate.

 *  Fix: Don't send both `If-None-Match` and `If-Modified-Since` cache headers
    when both are applicable.
 *  Fix: Fail early when a port is out of range.
 *  Fix: Offer `Content-Length` headers for multipart request bodies.
 *  Fix: Throw `UnknownServiceException` if a cleartext connection is attempted
    when explicitly forbidden.

    @Override
    public E element() {
      synchronized (mutex) {
        return delegate().element();
      }
    }

    @Override
    public boolean offer(E e) {
      synchronized (mutex) {
        return delegate().offer(e);
      }
    }

    @Override
    public @Nullable E peek() {
      synchronized (mutex) {
        return delegate().peek();
      }
    }

    @Override
    public E element() {
      synchronized (mutex) {
        return delegate().element();
      }
    }

    @Override
    public boolean offer(E e) {
      synchronized (mutex) {
        return delegate().offer(e);
      }
    }

    @Override
    public @Nullable E peek() {
      synchronized (mutex) {
        return delegate().peek();
      }
    }