* streams.
 *
 * <p><i>Performance notes:</i> Unless otherwise noted, all of the iterables produced in this class
 * are <i>lazy</i>, which means that their iterators only advance the backing iteration when
 * absolutely necessary.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#iterables">{@code
 * Iterables}</a>.
 *

 * [OkHttp Profiler](https://plugins.jetbrains.com/plugin/11249-okhttp-profiler): An IntelliJ plugin for monitoring OkHttp calls.
 * [OkReplay](https://github.com/airbnb/okreplay): Record and replay OkHttp network interaction in your tests.
 * [okhttp-signpost](https://github.com/pakerfeldt/okhttp-signpost): OAuth signing with signpost and OkHttp.
 * [okhttp-spring-boot](https://github.com/freefair/okhttp-spring-boot): Spring Boot starters for OkHttp

     * than once. The iteration order of the returned map is the order in which entries were
     * inserted into the builder, unless {@link #orderEntriesByValue} was called, in which case
     * entries are sorted by value. If a key was added more than once, it appears in iteration order
     * based on the first time it was added, again unless {@link #orderEntriesByValue} was called.

   * may be sent after response headers or body bytes have been received.
   *
   * Though any call may be initiated as a duplex call, only web servers that are specially
   * designed for this nonstandard interaction will use it. As of 2019-01, the only widely-used
   * implementation of this pattern is [gRPC][grpc].
   *
   * Because the encoding of interleaved data is not well-defined for HTTP/1, duplex request

  // Package-private so that it can be extended.
  MinimalCollection(Class<? super @NonNull E> type, boolean allowNulls, E... contents) {
    // TODO: consider making it shuffle the contents to test iteration order.
    this.contents = Platform.clone(contents);
    this.type = type;
    this.allowNulls = allowNulls;

    if (!allowNulls) {
      for (Object element : contents) {
        if (element == null) {

  /**
   * Helper method to create an array of the appropriate type used by this generator. The returned
   * array will contain only nulls.
   */
  E[] createArray(int length);

  /**
   * Returns the iteration ordering of elements, given the order in which they were added to the
   * container. This method may return the original list unchanged, the original list modified in
   * place, or a different list.
   *

     * than once. The iteration order of the returned map is the order in which entries were
     * inserted into the builder, unless {@link #orderEntriesByValue} was called, in which case
     * entries are sorted by value. If a key was added more than once, it appears in iteration order
     * based on the first time it was added, again unless {@link #orderEntriesByValue} was called.

        assertEquals(3.14, captured.get("double"));
        assertNotNull(captured.get("map"));
    }

    public void test_store_withCallbackInteraction() {
        // Test store with callback interaction
        final TestIndexUpdateCallback callback = new TestIndexUpdateCallback();

        dataStore = new DataStore() {
            @Override

 * good job of distributing the elements to the buckets to a distribution not far from uniform), and
 * amortized since some operations can trigger a hash table resize.
 *
 * <p>Unlike {@code java.util.HashSet}, iteration is only proportional to the actual {@code size()},
 * which is optimal, and <i>not</i> the size of the internal hashtable, which could be much larger

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: