ErrorCode.fromHttp2(errorCodeInt) ?: throw IOException(
        "TYPE_GOAWAY unexpected error code: $errorCodeInt",
      )
    var debugData = ByteString.EMPTY
    if (opaqueDataLength > 0) { // Must read debug data in order to not corrupt the connection.
      debugData = source.readByteString(opaqueDataLength.toLong())
    }
    handler.goAway(lastStreamId, errorCode, debugData)
  }