private val servers = mutableMapOf<String, MockWebServer>()
    private var started = false

    fun server(name: String): MockWebServer {
      return servers.getOrPut(name) {
        MockWebServer().also {
          if (started) it.start()
        }
      }
    }

    fun startAll() {
      started = true
      for (server in servers.values) {
        server.start()
      }
    }