/**
   * Degrades this connection such that new streams can neither be created locally, nor accepted
   * from the remote peer. Existing streams are not impacted. This is intended to permit an endpoint
   * to gracefully stop accepting new requests without harming previously established streams.
   */
  @Throws(IOException::class)
  fun shutdown(statusCode: ErrorCode) {
    writer.withLock {
      val lastGoodStreamId: Int