server.requireClientAuth()
    val call = client.newCall(Request.Builder().url(server.url("/")).build())
    assertFailsWith<IOException> {
      call.execute()
    }

    // Observed Events are variable
    // JDK 14
    // CallStart, ProxySelectStart, ProxySelectEnd, DnsStart, DnsEnd, ConnectStart, SecureConnectStart,
    // SecureConnectEnd, ConnectEnd, ConnectionAcquired, RequestHeadersStart, RequestHeadersEnd,

    @Throws(IOException::class)
    fun parse(responseHeaders: Headers): WebSocketExtensions {
      // Note that this code does case-insensitive comparisons, even though the spec doesn't specify
      // whether extension tokens and parameters are case-insensitive or not.

      var compressionEnabled = false
      var clientMaxWindowBits: Int? = null

 * if (forceCacheResponse.code() != 504) {
 *   // The resource was cached! Show it.
 * } else {
 *   // The resource was not cached.
 * }
 * ```
 *
 * This technique works even better in situations where a stale response is better than no response.
 * To permit stale cached responses, use the `max-stale` directive with the maximum staleness in
 * seconds:
 *
 * ```java

    fun build(): Headers = commonBuild()
  }

  companion object {
    /**
     * Returns headers for the alternating header names and values. There must be an even number of
     * arguments, and they must alternate between header names and values.
     */
    @JvmStatic
    @JvmName("of")
    fun headersOf(vararg namesAndValues: String): Headers = commonHeadersOf(*namesAndValues)

        HTTP_PROXY_AUTH -> "Proxy-Authenticate"
        else -> return emptyList()
      },
    )
  }

  /**
   * Returns the cache control directives for this response. This is never null, even if this
   * response contains no `Cache-Control` header.
   */
  @get:JvmName("cacheControl")
  val cacheControl: CacheControl
    get() = commonCacheControl

  @JvmName("-deprecated_cacheControl")

    override fun closes(event: CallEvent): Boolean = event is CallStart && call == event.call
  }

  data class CallFailed(
    override val timestampNs: Long,
    override val call: Call,
    val ioe: IOException,
  ) : CallEvent() {
    override fun closes(event: CallEvent): Boolean = event is CallStart && call == event.call
  }

  data class Canceled(
    override val timestampNs: Long,

OkHttp Server-Sent Events
=========================

Experimental support for server-sent events.
API is not considered stable and may change at any time.

### Download

```kotlin
testImplementation("com.squareup.okhttp3:okhttp-sse:4.12.0")

import okhttp3.Request

object RequestLine {
  /**
   * Returns the request status line, like "GET / HTTP/1.1". This is exposed to the application by
   * [HttpURLConnection.getHeaderFields], so it needs to be set even if the transport is
   * HTTP/2.
   */
  fun get(
    request: Request,
    proxyType: Proxy.Type,
  ): String =
    buildString {
      append(request.method)
      append(' ')

/**
 * Integration test to confirm that [TaskRunner] works with a real backend. Business logic is all
 * exercised by [TaskRunnerTest].
 *
 * This test is doing real sleeping with tolerances of 250 ms. Hopefully that's enough for even the
 * busiest of CI servers.
 */
@Tag("Slowish")
class TaskRunnerRealBackendTest {
  private val log = LinkedBlockingDeque<String>()

  private val loggingUncaughtExceptionHandler =

   *
   * Configure the client's default timeout with [OkHttpClient.Builder.callTimeout].
   */
  fun timeout(): Timeout

  /**
   * Create a new, identical call to this one which can be enqueued or executed even if this call
   * has already been.
   */
  public override fun clone(): Call

  fun interface Factory {
    fun newCall(request: Request): Call
  }