val callsToExecute = mutableListOf<AsyncCall>()
        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()

          asyncCall.callsPerHost.incrementAndGet()

    )

  internal fun redactedUrl(): String = originalRequest.url.redact()

  inner class AsyncCall(
    private val responseCallback: Callback,
  ) : Runnable {
    @Volatile var callsPerHost = AtomicInteger(0)
      private set

    fun reuseCallsPerHostFrom(other: AsyncCall) {
      this.callsPerHost = other.callsPerHost
    }

    val host: String
      get() = originalRequest.url.host

    newWebSocket()
    serverListener.assertOpen()
    serverListener.assertFailure(EOFException::class.java)
    serverListener.assertExhausted()
    clientListener.assertFailure(e)
  }

  @Disabled("AsyncCall currently lets runtime exceptions propagate.")
  @Test
  @Throws(
    Exception::class,
  )
  fun throwingOnFailLogs() {
    webServer.enqueue(
      MockResponse
        .Builder()