code: func EncodeRxCompletion(b []byte, size, reserved uint32) {
  	binary.LittleEndian.PutUint32(b[consumedPacketSize:], size)
  	binary.LittleEndian.PutUint32(b[consumedPacketReserved:], reserved)
  }
docs: // EncodeRxCompletion encodes an rx completion header.