encodings[ 0xf] = encoding // Shift In
      encodings[ 0x10] = encoding // Data Link Escape
      encodings[ 0x11] = encoding // Device Control 1 (oft. XON)
      encodings[ 0x12] = encoding // Device Control 2
      encodings[ 0x13] = encoding // Device Control 3 (oft. XOFF)
      encodings[ 0x14] = encoding // Device Control 4
      encodings[ 0x15] = encoding // Negative Acknowledgment
      encodings[ 0x16] = encoding // Synchronous idle

 * class to read a response that is larger than the entire memory allocated to the current process.
 * It can even stream a response larger than the total storage on the current device, which is a
 * common requirement for video streaming applications.
 *
 * Because this class does not buffer the full response in memory, the application may not

    server.enqueue(MockResponse().setSocketPolicy(SocketPolicy.DISCONNECT_DURING_REQUEST_BODY))
    // Limit the size of the request body that the server holds in memory to an arbitrary
    // 3.5 MBytes so this test can pass on devices with little memory.
    server.bodyLimit = 7 * 512 * 1024
    val connection = server.url("/").toUrl().openConnection() as HttpURLConnection
    connection.setRequestMethod("POST")
    connection.setDoOutput(true)

    val client = makeClient()
    makeRequest(client)

    // As of OkHttp 5 we now apply the ordering from the OkHttpClient, which defaults to MODERN_TLS
    // Clients might need a changed order, but can at least define a preferred order to override that default.
    val socketOrderedByDefaults =
      handshakeEnabledCipherSuites.sortedBy { ConnectionSpec.MODERN_TLS.cipherSuitesAsString!!.indexOf(it) }

  @ValueSource(booleans = [false, true])
  fun proxyMoveTest(cleanShutdown: Boolean) {
    // Define a single Proxy at myproxy:8008 that will artificially move during the test
    val proxySelector = RecordingProxySelector()
    proxySelector.proxies.add(Proxy(Proxy.Type.HTTP, InetSocketAddress("myproxy", 8008)))

    // Define two host names for the DNS routing of fake proxy servers

   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we
   * expect a newly-started thread to call [Runnable.run]. We shouldn't request new threads until
   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *
   * We use [executeCallCount] and [runCallCount] to defend against starting more threads than we
   * need. Both fields are guarded by [lock].
   */

    open fun headers(headers: Headers) = commonHeaders(headers)

    /**
     * Sets this request's `Cache-Control` header, replacing any cache control headers already
     * present. If [cacheControl] doesn't define any directives, this clears this request's
     * cache-control headers.
     */
    open fun cacheControl(cacheControl: CacheControl): Builder = commonCacheControl(cacheControl)

    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`.

    val existingRouteSelection = routeSelection
    if (existingRouteSelection != null && existingRouteSelection.hasNext()) {
      return planConnectToRoute(existingRouteSelection.next())
    }

    // Decide which proxy to use, if any. This may block in ProxySelector.select().
    var newRouteSelector = routeSelector
    if (newRouteSelector == null) {
      newRouteSelector =
        RouteSelector(

You can check a web server's configuration using [Qualys SSL Labs][qualys]. OkHttp's TLS
configuration history is [tracked here](../security/tls_configuration_history.md).

Applications expected to be installed on older Android devices should consider adopting the
[Google Play Services’ ProviderInstaller][provider_installer]. This will increase security for users
and increase connectivity with web servers.