* a CountdownLatch).
   */
  @Throws(InterruptedException::class)
  abstract fun dispatch(request: RecordedRequest): MockResponse

  /**
   * Returns an early guess of the next response, used for policy on how an incoming request should
   * be received. The default implementation returns an empty response. Mischievous implementations

    val executableCalls = mutableListOf<AsyncCall>()
    val isRunning: Boolean
    this.withLock {
      val i = readyAsyncCalls.iterator()
      while (i.hasNext()) {
        val asyncCall = i.next()

        if (runningAsyncCalls.size >= this.maxRequests) break // Max capacity.
        if (asyncCall.callsPerHost.get() >= this.maxRequestsPerHost) continue // Host max capacity.

        i.remove()