* {@link SortedMultiset#tailMultiset}, the {@code size()} and {@code iterator()} methods of
   * {@link SortedMultiset#entrySet}, and {@link SortedMultiset#remove(Object, int)}. In many
   * situations, you may wish to override {@link SortedMultiset#elementSet} to forward to this
   * implementation or a subclass thereof.
   *
   * @since 15.0
   */

testing everything. You can even copy & paste HTTP responses from your real web
server to create representative test cases. Or test that your code survives in
awkward-to-reproduce situations like 500 errors or slow-loading responses.


### Example

Use MockWebServer the same way that you use mocking frameworks like
[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.

    url: HttpUrl,
  ) {
  }

  /**
   * Invoked after proxy selection.
   *
   * Note that the list of proxies is never null, but it may be a list containing
   * only [Proxy.NO_PROXY]. This comes up in several situations:
   *
   * * If neither a proxy nor proxy selector is configured.
   * * If the proxy is configured explicitly as [Proxy.NO_PROXY].
   * * If the proxy selector returns only [Proxy.NO_PROXY].

 * responses. Although this client honors all [HTTP/1.1 (RFC 7234)][rfc_7234] cache headers, it
 * doesn't cache partial responses.
 *
 * ## Force a Network Response
 *
 * In some situations, such as after a user clicks a 'refresh' button, it may be necessary to skip
 * the cache, and fetch data directly from the server. To force a full refresh, add the `no-cache`
 * directive:
 *
 * ```java

     *
     * <p><b>Performance note:</b> {@link ArrayList} and {@link java.util.ArrayDeque} consistently
     * 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}.)

     *
     * <p><b>Performance note:</b> {@link ArrayList} and {@link java.util.ArrayDeque} consistently
     * 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}.)

   * instead.
   *
   * <p><b>Performance note:</b> {@link ArrayList} and {@link java.util.ArrayDeque} consistently
   * 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.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,

 *  New: We've added `requestFailed()` and `responseFailed()` methods to `EventListener`. These
    are called instead of `requestBodyEnd()` and `responseBodyEnd()` in some failure situations.
    They may also be fired in cases where no event was published previously. In this release we did
    an internal rewrite of our event code to fix problems where events were lost or unbalanced.

    when a request body needs to cancel its own call.


## Version 4.2.1

_2019-10-02_

 *  Fix: In 4.1.0 we introduced a performance regression that prevented connections from being
    pooled in certain situations. We have good test coverage for connection pooling but we missed
    this because it only occurs if you have proxy configured and you share a connection pool among
    multiple `OkHttpClient` instances.

    logs.

 *  **WebSocket API now uses `RequestBody` and `ResponseBody` for messages.**
    This is a backwards-incompatible API change.

 *  **The DNS service is now pluggable.** In some situations this may be useful
    to manually prioritize specific IP addresses.

 *  Fix: Don't throw when converting an `HttpUrl` to a `java.net.URI`.
    Previously URLs with special characters like `|` and `[` would break when