Upgrading to OkHttp 4
=====================

OkHttp 4.x upgrades our implementation language from Java to Kotlin and keeps everything else the
same. We’ve chosen Kotlin because it gives us powerful new capabilities while integrating closely
with Java.

We spent a lot of time and energy on retaining strict compatibility with OkHttp 3.x. We’re even
keeping the package name the same: `okhttp3`!

There are three kinds of compatibility we’re tracking:

import java.util.stream.Stream;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * An expanded {@code Iterable} API, providing functionality similar to Java 8's powerful <a href=
 * "https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html#package.description"
 * >streams library</a> in a slightly different way.
 *
 * <p>The following types of methods are provided:
 *

                          type: string
                          example: "Docs » Open Source Enterprise Search Server: Fess Commercial Support Open Source Enterprise Search Server: Fess What is Fess ? Fess is very powerful and easily deployable Enterprise Search Server. ..."
                        host:
                          type: string
                          format: hostname
                          example: "fess.codelibs.org"

 * Iterables} class.
 *
 * <p><a id="streams"></a>
 *
 * <h3>Comparison to streams</h3>
 *
 * <p>{@link Stream} is similar to this class, but generally more powerful, and certainly more
 * standard. Key differences include:
 *
 * <ul>
 *   <li>A stream is <i>single-use</i>; it becomes invalid as soon as any "terminal operation" such

 * appropriate {@code copyOf} method itself.
 *
 * <p>Expressing the immutability guarantee directly in the type that user code references is a
 * powerful advantage. Although Java offers certain immutable collection factory methods, such as
 * {@link Collections#singleton(Object)} and <a
 * href="https://docs.oracle.com/javase/9/docs/api/java/util/Set.html#immutable">{@code Set.of}</a>,

 * appropriate {@code copyOf} method itself.
 *
 * <p>Expressing the immutability guarantee directly in the type that user code references is a
 * powerful advantage. Although Java offers certain immutable collection factory methods, such as
 * {@link Collections#singleton(Object)} and <a
 * href="https://docs.oracle.com/javase/9/docs/api/java/util/Set.html#immutable">{@code Set.of}</a>,

    HTTPS connection. If you continue to need to connect to webservers
    running SSLv3, you must manually configure your own `ConnectionSpec`.

 *  **OkHttp now offers interceptors.** Interceptors are a powerful mechanism
    that can monitor, rewrite, and retry calls. The [interceptors doc][interceptors] is a full
    introduction to this new API.

 *  New: APIs to iterate and selectively clear the response cache.