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/cds/sdk
    
    the code of the file until where you have to start completion: package sdk

import (
	"crypto/rand"
	"fmt"
	"io"

	"github.com/pborman/uuid"
)

// UUID returns a UUID v4
func UUID() string {
	uuID := make([]byte, 16)
	n, err := io.ReadFull(rand.Reader, uuID)
	if n != len
    
func UUID() string {
	uuID := make([]byte, 16)
	n, err := io.ReadFull(rand.Reader, uuID)
	if n != len(uuID) || err != nil {
		panic(err)
	}
	// variant bits; see section 4.1.1
	uuID[8] = uuID[8]&^0xc0 | 0x80
	// version 4 (pseudo-random); see section 4.1.3
	uuID[6] = uuID[6]&^0xf0 | 0x40
	return fmt.Sprintf("%x-%x-%x-%x-%x", uuID[0:4], uuID[4:6], uuID[6:8], uuID[8:10], uuID[10:])
}