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

    val request: Request
      get() = originalRequest

          // the same host.
          if (!enqueuedCall.call.forWebSocket) {
            val existingCall = findExistingCallWithHost(enqueuedCall.host)
            if (existingCall != null) enqueuedCall.reuseCallsPerHostFrom(existingCall)
          }
        }

        val becameIdle =
          (finishedCall != null || finishedAsyncCall != null) &&
            (executorIsShutdown || runningAsyncCalls.isEmpty()) &&