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),

  INADEQUATE_SECURITY(0xc),

    length: Int,
    flags: Int,
    streamId: Int,
  ) {
    if (streamId == 0) throw IOException("PROTOCOL_ERROR: TYPE_DATA streamId == 0")

    // TODO: checkState open or half-closed (local) or raise STREAM_CLOSED
    val inFinished = flags and FLAG_END_STREAM != 0
    val gzipped = flags and FLAG_COMPRESSED != 0
    if (gzipped) {
      throw IOException("PROTOCOL_ERROR: FLAG_COMPRESSED without SETTINGS_COMPRESS_DATA")
    }