code: func EncodeRxCompletionBuffer(b []byte, i int, rxb RxBuffer) {
  	b = b[RxCompletionSize(i):]
  	binary.LittleEndian.PutUint64(b[consumedOffset:], rxb.Offset)
  	binary.LittleEndian.PutUint32(b[consumedSize:], rxb.Size)
  	binary.LittleEndian.PutUint64(b[consumedUserData:], rxb.UserData)
  	binary.LittleEndian.PutUint64(b[consumedID:], rxb.ID)
  }
docs: // EncodeRxCompletionBuffer encodes the i-th rx completion buffer header.