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:

 * **Binary compatibility** is the ability to compile a program against OkHttp 3.x, and then to run

        table[tableIndex] = effectiveEntry;
      } else {
        // We already saw this key, and the first value we saw (going backwards) is the one we are
        // keeping. So we won't touch table[], but we do still want to add the existing entry that
        // we found to entries[] so that we will see this key in the right place when iterating.
        if (duplicates == null) {

    //                                                                           Attribute
    //                                                                           =========
    // keeping parsed request parameters, normal texts or uploaded files
    // keys are requested parameter names (treated as field name here)
    protected Map<String, Object> elementsAll; // lazy-loaded, then after not null

   * reconstructed using public factory methods. This ensures that the implementation types remain
   * as implementation details.
   *
   * <p>Since the bimap is immutable, ImmutableBiMap doesn't require special logic for keeping the
   * bimap and its inverse in sync during serialization, the way AbstractBiMap does.
   */
  @J2ktIncompatible // serialization
  private static final class SerializedForm<K, V> extends ImmutableMap.SerializedForm<K, V> {

        }

        /**
         * Deletes old documents from the search index.
         * This method removes documents that were indexed in previous
         * crawling sessions for the same data configuration, keeping
         * only the documents from the current session.
         *
         * <p>The deletion process:</p>
         * <ul>
         *   <li>Checks if old document deletion is enabled</li>

 * is intended solely to help find problems during development.
 *
 * <p>The EventBus guarantees that it will not call a subscriber method from multiple threads
 * simultaneously, unless the method explicitly allows it by bearing the {@link
 * AllowConcurrentEvents} annotation. If this annotation is not present, subscriber methods need not
 * worry about being reentrant, unless also called from outside the EventBus.
 *
 * <h2>Dead Events</h2>
 *

**OkHttp now supports Happy Eyeballs ([RFC 8305][rfc_8305]) for IPv4+IPv6 networks.** It attempts
both IPv6 and IPv4 connections concurrently, keeping whichever connects first.

**We’ve improved our Kotlin APIs.** You can skip the builder:

```kotlin
val request = Request(
  url = "https://cash.app/".toHttpUrl(),
)
```

**OkHttp now supports [GraalVM].**

  // The `table` array always has a size that is a power of 2. The hashcode of a key in the map
  // is masked in order to correspond to the current table size. For example, if the table size
  // is 128 then the mask is 127 == 0x7f, keeping the bottom 7 bits of the hash value.
  // If a key hashes to 0x89abcdef the mask reduces it to 0x89abcdef & 0x7f == 0x6f. We'll call this
  // the "short hash".
  //

   * - System.nanoTime() is expensive enough that we want to call it the minimum required number of
   *   times, typically once before invoking a blocking method. This often requires keeping track of
   *   the first time in a method that nanoTime() has been invoked, for which the special value 0L
   *   is reserved to mean "uninitialized". If timeout is non-positive, then nanoTime need never be
   *   called.

  // The `table` array always has a size that is a power of 2. The hashcode of a key in the map
  // is masked in order to correspond to the current table size. For example, if the table size
  // is 128 then the mask is 127 == 0x7f, keeping the bottom 7 bits of the hash value.
  // If a key hashes to 0x89abcdef the mask reduces it to 0x89abcdef & 0x7f == 0x6f. We'll call this
  // the "short hash".
  //