* that it is not "API-frozen."
 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */
@Retention(RetentionPolicy.CLASS)

 * that it is not "API-frozen."
 *
 * <p>It is generally safe for <i>applications</i> to depend on beta APIs, at the cost of some extra
 * work during upgrades. However it is generally inadvisable for <i>libraries</i> (which get
 * included on users' CLASSPATHs, outside the library developers' control) to do so.
 *
 * @author Kevin Bourrillion
 */
@Retention(RetentionPolicy.CLASS)

      }

      val isUpgradeResponse =
        isUpgradeCode &&
          "upgrade".equals(response.header("Connection"), ignoreCase = true)

      response =
        when {
          // This is an HTTP/1 upgrade. (This case includes web socket upgrades.)
          isUpgradeRequest && isUpgradeResponse -> {
            response
              .newBuilder()
              .body(

  }

  @Test
  fun upgradeHttps() {
    enableTls(Protocol.HTTP_1_1)
    upgrade()
  }

  @Test
  fun upgradeRefusedByServer() {
    server.enqueue(MockResponse(body = "normal request"))
    val requestWithUpgrade =
      Request
        .Builder()
        .url(server.url("/"))
        .header("Connection", "upgrade")
        .build()
    client.newCall(requestWithUpgrade).execute().use { response ->

  }

  @Test fun http2HeadersListDropsForbiddenHeadersHttp2() {
    val request =
      Request
        .Builder()
        .url("http://square.com/")
        .header("Connection", "upgrade")
        .header("Upgrade", "websocket")
        .header("Host", "square.com")
        .header("TE", "gzip")
        .build()
    val expected =
      headerEntries(
        ":method",
        "GET",
        ":path",

    assertThat(recorded.headers["Connection"]).isEqualTo("Upgrade, HTTP2-Settings")
    if (PlatformVersion.majorVersion < 19) {
      assertThat(recorded.headers["Content-Length"]).isEqualTo("0")
    }
    assertThat(recorded.headers["HTTP2-Settings"]).isNotNull()
    assertThat(recorded.headers["Upgrade"]).isEqualTo("h2c") // HTTP/2 over plaintext!

   * MoreExecutors#listeningDecorator( java.util.concurrent.ExecutorService)}, {@link
   * ListenableFutureTask}, {@link AbstractFuture}, and other utilities over creating plain {@code
   * Future} instances to be upgraded to {@code ListenableFuture} after the fact.
   */
  public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(
      Future<V> future) {
    if (future instanceof ListenableFuture) {

    private const val UPGRADE = "upgrade"

    /** See http://tools.ietf.org/html/draft-ietf-httpbis-http2-09#section-8.1.3. */
    private val HTTP_2_SKIPPED_REQUEST_HEADERS =
      immutableListOf(
        CONNECTION,
        HOST,
        KEEP_ALIVE,
        PROXY_CONNECTION,
        TE,
        TRANSFER_ENCODING,
        ENCODING,
        UPGRADE,
        TARGET_METHOD_UTF8,

      this.settings = settings
    }

  fun withWebSocketUpgrade(listener: WebSocketListener) =
    apply {
      status = "HTTP/1.1 101 Switching Protocols"
      setHeader("Connection", "Upgrade")
      setHeader("Upgrade", "websocket")
      body = null
      webSocketListener = listener
    }

  override fun toString(): String = status

  companion object {

   * Servers that enforce this may send an exception message including the string
   * `INADEQUATE_SECURITY`.
   */
  HTTP_2("h2"),

  /**
   * Cleartext HTTP/2 with no "upgrade" round trip. This option requires the client to have prior
   * knowledge that the server supports cleartext HTTP/2.
   *
   * See also [Starting HTTP/2 with Prior Knowledge][rfc_7540_34].
   *