supply trailers for a `Response`.

 *  New: `Path.asRequestBody()` is now a non-experimental API.

 *  New: `FileDescriptor.toRequestBody()` is now a non-experimental API.

 *  New: Stop using experimental coroutines APIs in our `okhttp-coroutines` artifact.

 *  Breaking: Move `gzip` from `RequestBody` to `Request.Builder`. This new API handles both

  - [Downloads for v1.2.0](#downloads-for-v120)
  - [Changes since v1.1.1](#changes-since-v111)
    - [Major Themes](#major-themes)
    - [Other notable improvements](#other-notable-improvements)
    - [Experimental Features](#experimental-features)
    - [Action required](#action-required-1)
    - [Known Issues](#known-issues)
      - [Docker Known Issues](#docker-known-issues)
        - [1.9.1](#191)

    frame.writeByte(Http2.TYPE_SETTINGS)
    frame.writeByte(FLAG_NONE)
    frame.writeInt(0) // Settings are always on the connection stream 0.
    frame.write("f000".decodeHex()) // Id reserved for experimental use.
    frame.writeInt(1)
    reader.nextFrame(
      requireSettings = false,
      object : BaseTestHandler() {
        override fun settings(
          clearPrevious: Boolean,

   * files with extension "PSB" are in a distinct but related format).
   *
   * <p>This is a more recent replacement for the older, experimental type {@code x-photoshop}: <a
   * href="http://tools.ietf.org/html/rfc2046#section-6">RFC-2046.6</a>.
   *
   * @since 15.0
   */

  /**
   * The HTTP <a
   * href="https://wicg.github.io/user-preference-media-features-headers/#sec-ch-prefers-color-scheme">{@code
   * Sec-CH-Prefers-Color-Scheme}</a> header field name.
   *
   * <p>This header is experimental.
   *
   * @since 31.0
   */
  public static final String SEC_CH_PREFERS_COLOR_SCHEME = "Sec-CH-Prefers-Color-Scheme";

  /**
   * The HTTP <a

   * files with extension "PSB" are in a distinct but related format).
   *
   * <p>This is a more recent replacement for the older, experimental type {@code x-photoshop}: <a
   * href="http://tools.ietf.org/html/rfc2046#section-6">RFC-2046.6</a>.
   *
   * @since 15.0
   */

   * input.
   */
  @VisibleForTesting static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.HashMap based
   * implementation. Experimentally determined.
   */
  static final int MAX_HASH_BUCKET_LENGTH = 8;

  // entries in insertion order
  @VisibleForTesting final transient Entry<K, V>[] entries;
  // array of linked lists of entries

     * wrapper around j.u.HashSet, which has built-in flooding protection. MAX_RUN_MULTIPLIER was
     * determined experimentally to match our desired probability of false positives.
     */
    // NB: yes, this is surprisingly high, but that's what the experiments said was necessary
    // Raising this number slows the worst-case contains behavior, speeds up hashFloodingDetected,

  @VisibleForTesting(
      )
  static final double HASH_FLOODING_FPP = 0.001;

  /**
   * Maximum allowed length of a hash table bucket before falling back to a j.u.LinkedHashSet based
   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;

  // See CompactHashMap for a detailed description of how the following fields work. That

     * both say in their comments that they're not really sure what the right approach is. We go
     * with Chrome's behavior (which also experimentally seems to match what IE does), but if you
     * actually want to have a good chance of things working, please avoid double-quotes, newlines,
     * percent signs, and the like in your field names.
     */