}
    }
    ```

 *  New: `MediaType.parameter()` gets a parameter like `boundary` from a media type like
    `multipart/mixed; boundary="abc"`.

 *  New: `Authenticator.JAVA_NET_AUTHENTICATOR` forwards authentication requests to
    `java.net.Authenticator`. This obsoletes `JavaNetAuthenticator` in the `okhttp-urlconnection`
    module.

 *  New: `CertificatePinner` now offers an API for inspecting the configured pins.

        .authenticator(authenticator)
        .build()
    executeSynchronously("/")
      .assertCode(401)
    assertThat(authenticator.onlyRoute()).isNotNull()
  }

  @Test
  fun delete() {
    server.enqueue(MockResponse(body = "abc"))
    val request =
      Request.Builder()
        .url(server.url("/"))
        .delete()
        .build()
    executeSynchronously(request)

      when (response.code) {
        HttpURLConnection.HTTP_OK -> return null

        HttpURLConnection.HTTP_PROXY_AUTH -> {
          nextRequest = route.address.proxyAuthenticator.authenticate(route, response)
            ?: throw IOException("Failed to authenticate with proxy")

          if ("close".equals(response.header("Connection"), ignoreCase = true)) {
            return nextRequest
          }
        }

  var taskRunner: TaskRunner = taskFaker.taskRunner
  var dns: Dns = Dns.SYSTEM
  var proxy: Proxy = Proxy.NO_PROXY
  var proxySelector: ProxySelector = RecordingProxySelector()
  var proxyAuthenticator: Authenticator = RecordingOkAuthenticator("password", null)
  var connectionSpecs: List<ConnectionSpec> =
    listOf(
      ConnectionSpec.MODERN_TLS,
      ConnectionSpec.COMPATIBLE_TLS,
      ConnectionSpec.CLEARTEXT,
    )

  @ArgumentsSource(ProtocolParamProvider::class)
  fun authenticate(
    protocol: Protocol,
    mockWebServer: MockWebServer,
  ) {
    setUp(protocol, mockWebServer)
    server.enqueue(
      MockResponse(
        code = HttpURLConnection.HTTP_UNAUTHORIZED,
        headers = headersOf("www-authenticate", "Basic realm=\"protected area\""),
        body = "Please authenticate.",
      ),
    )
    server.enqueue(

     */
    private fun isEndToEnd(fieldName: String): Boolean {
      return !"Connection".equals(fieldName, ignoreCase = true) &&
        !"Keep-Alive".equals(fieldName, ignoreCase = true) &&
        !"Proxy-Authenticate".equals(fieldName, ignoreCase = true) &&
        !"Proxy-Authorization".equals(fieldName, ignoreCase = true) &&
        !"TE".equals(fieldName, ignoreCase = true) &&
        !"Trailers".equals(fieldName, ignoreCase = true) &&

        .code(HttpURLConnection.HTTP_PROXY_AUTH)
        .message("Preemptive Authenticate")
        .sentRequestAtMillis(-1L)
        .receivedResponseAtMillis(-1L)
        .header("Proxy-Authenticate", "OkHttp-Preemptive")
        .build()

    val authenticatedRequest =
      route.address.proxyAuthenticator
        .authenticate(route, fakeAuthChallengeResponse)

    return authenticatedRequest ?: proxyConnectRequest

    val heldCertificate: HeldCertificate = builder.build()
  }

  @Test
  fun javaNetAuthenticator() {
    val authenticator = JavaNetAuthenticator()
    val response = Response.Builder().build()
    var request: Request? = authenticator.authenticate(factory.newRoute(), response)
    request = authenticator.authenticate(null, response)
  }

  @Test
  fun javaNetCookieJar() {

          throw ProtocolException("Received HTTP_PROXY_AUTH (407) code while not using proxy")
        }
        return client.proxyAuthenticator.authenticate(route, userResponse)
      }

      HTTP_UNAUTHORIZED -> return client.authenticator.authenticate(route, userResponse)

      HTTP_PERM_REDIRECT, HTTP_TEMP_REDIRECT, HTTP_MULT_CHOICE, HTTP_MOVED_PERM, HTTP_MOVED_TEMP, HTTP_SEE_OTHER -> {

      }

    /**
     * Sets the authenticator used to respond to challenges from origin servers. Use
     * [proxyAuthenticator] to set the authenticator for proxy servers.
     *
     * If unset, the [no authentication will be attempted][Authenticator.NONE].
     */
    fun authenticator(authenticator: Authenticator) =
      apply {
        this.authenticator = authenticator
      }