assertEquals(SimpleCircuitBreaker.State.OPEN, circuitBreaker.getState());

        // Wait for timeout
        Thread.sleep(150);

        // Next call should transition to HALF_OPEN
        String result = circuitBreaker.call(() -> "success");
        assertEquals("success", result);
        assertEquals(SimpleCircuitBreaker.State.HALF_OPEN, circuitBreaker.getState());
    }

    @Test

) : EventSource,
  ServerSentEventReader.Callback,
  Callback {
  constructor(call: Call, listener: EventSourceListener) : this(call, call.request(), listener)

  constructor(response: Response, listener: EventSourceListener) : this(null, response.request, listener)

  @Volatile private var canceled = false

  override fun onResponse(
    call: Call,
    response: Response,
  ) {
    processResponse(response)
  }

// Stat captures time taken to call os.Stat
func Stat(name string) (info os.FileInfo, err error) {
	defer updateOSMetrics(osMetricStat, name)(err)
	return os.Stat(name)
}

// Create captures time taken to call os.Create
func Create(name string) (f *os.File, err error) {
	defer updateOSMetrics(osMetricCreate, name)(err)
	return os.Create(name)
}

// Fdatasync captures time taken to call Fdatasync

        .setSocketPolicy(SocketPolicy.STALL_SOCKET_AT_START),
    )
    server.start()
    val call =
      client.newCall(
        Request
          .Builder()
          .url(server.url("/"))
          .build(),
      )
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: okio.IOException,
        ) {
          callFailure.complete(e)
        }

An example could be that you have an external authentication provider that you need to call.

You send it a token and it returns an authenticated user.

This provider might be charging you per request, and calling it might take some extra time than if you had a fixed mock user for tests.

You probably want to test the external provider once, but not necessarily call it for every test that runs.

    fun newEventSource(
      request: Request,
      listener: EventSourceListener,
    ): EventSource

    companion object {
      /**
       * Wraps a [Call.Factory] into [EventSource.Factory].
       */
      @JvmStatic
      @JvmName("create")
      fun Call.Factory.asEventSourceFactory(): Factory =
        Factory { request, listener ->
          val actualRequest =
            if (request.header("Accept") == null) {

    client.newCall(Request(url)).enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          println("failed: $e")
        }

        override fun onResponse(
          call: Call,
          response: Response,
        ) {
          println("response: ${response.code}")
          response.close()
        }
      },

  // the call, but they may be accessed by other threads for duplex requests.

  /** True if this call still has a request body open. */
  private var requestBodyOpen = false

  /** True if this call still has a response body open. */
  private var responseBodyOpen = false

  /** True if there are more exchanges expected for this call. */
  private var expectMoreExchanges = true

	public abstract fun cancel ()V
	public static fun enqueue (Lokhttp3/Call;Lokhttp3/sse/EventSourceListener;)Lokhttp3/sse/EventSource;
	public static fun process (Lokhttp3/Response;Lokhttp3/sse/EventSourceListener;)V
	public abstract fun request ()Lokhttp3/Request;
}

public final class okhttp3/sse/EventSource$Companion {
	public final fun enqueue (Lokhttp3/Call;Lokhttp3/sse/EventSourceListener;)Lokhttp3/sse/EventSource;

	Speedtest bool // object call specifically meant for SpeedTest code, set to 'true' when invoked by SpeedtestHandler.

	// Use the maximum parity (N/2), used when saving server configuration files
	MaxParity bool

	// Provides a per object encryption function, allowing metadata encryption.
	EncryptFn objectMetaEncryptFn

	// SkipDecommissioned set to 'true' if the call requires skipping the pool being decommissioned.