var serverSocketFactory: ServerSocketFactory? = null
    @Synchronized get() {
      if (field == null && started) {
        field = ServerSocketFactory.getDefault() // Build the default value lazily.
      }
      return field
    }

    @Synchronized set(value) {
      check(!started) { "serverSocketFactory must not be set after start()" }
      field = value
    }

    get() = delegate.protocols
    set(value) {
      delegate.protocols = value
    }

  init {
    delegate.dispatcher = dispatcher.wrap()
  }

  private var started: Boolean = false

  @Synchronized override fun before() {
    if (started) return
    try {
      start()
    } catch (e: IOException) {
      throw RuntimeException(e)
    }
  }

  @JvmName("-deprecated_port")
  @Deprecated(