* request bodies.
   */
  open fun peek(): MockResponse {
    return MockResponse(socketPolicy = KeepOpen)
  }

  /**
   * Release any resources held by this dispatcher. Any requests that are currently being dispatched
   * should return immediately. Responses returned after shutdown will not be transmitted: their
   * socket connections have already been closed.
   */
  open fun shutdown() {}

  private val readyAsyncCalls = ArrayDeque<AsyncCall>()

  /** Running asynchronous calls. Includes canceled calls that haven't finished yet. */
  private val runningAsyncCalls = ArrayDeque<AsyncCall>()

  /** Running synchronous calls. Includes canceled calls that haven't finished yet. */
  private val runningSyncCalls = ArrayDeque<RealCall>()

  constructor(executorService: ExecutorService) : this() {