enum class ErrorCode constructor(
  val httpCode: Int,
) {
  /** Not an error!  */
  NO_ERROR(0),

  PROTOCOL_ERROR(1),

  INTERNAL_ERROR(2),

  FLOW_CONTROL_ERROR(3),

  SETTINGS_TIMEOUT(4),

  STREAM_CLOSED(5),

  FRAME_SIZE_ERROR(6),

  REFUSED_STREAM(7),

  CANCEL(8),

  COMPRESSION_ERROR(9),

  CONNECT_ERROR(0xa),

  ENHANCE_YOUR_CALM(0xb),

            stream.addBytesToWriteWindow(delta)
          }
        }
      }
    }

    override fun ackSettings() {
      // TODO: If we don't get this callback after sending settings to the peer, SETTINGS_TIMEOUT.
    }

    override fun ping(
      ack: Boolean,
      payload1: Int,
      payload2: Int,
    ) {
      if (ack) {
        withLock {
          when (payload1) {