You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: uuid.go
    path of file: ./repos/plumber/vendor/github.com/hashicorp/go-uuid
    
    the code of the file until where you have to start completion: package uuid

import (
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"io"
)

// GenerateRandomBytes is used to generate random bytes of given size.
func GenerateRandomBytes(size int) ([]byte, error) {
	return GenerateRandomBytesWithReader(size, rand.Reader)
}

// GenerateRandomBytesWithReader
    
func ParseUUID(uuid string) ([]byte, error) {
	if len(uuid) != 2 * uuidLen + 4 {
		return nil, fmt.Errorf("uuid string is wrong length")
	}

	if uuid[8] != '-' ||
		uuid[13] != '-' ||
		uuid[18] != '-' ||
		uuid[23] != '-' {
		return nil, fmt.Errorf("uuid is improperly formatted")
	}

	hexStr := uuid[0:8] + uuid[9:13] + uuid[14:18] + uuid[19:23] + uuid[24:36]

	ret, err := hex.DecodeString(hexStr)
	if err != nil {
		return nil, err
	}
	if len(ret) != uuidLen {
		return nil, fmt.Errorf("decoded hex is the wrong length")
	}

	return ret, nil
}