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: example_test.go
    path of file: ./repos/gitkube/vendor/golang.org/x/crypto/nacl/secretbox
    
    the code of the file until where you have to start completion: // Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package secretbox_test

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

	"golang.org/x/crypto/nacl/secretbox"
)

func Example() {
	// Load your secret key from a safe place and reuse it across multiple
	// Seal calls. (Obviously don't use this example key for anyt
    
func Example() {
	// Load your secret key from a safe place and reuse it across multiple
	// Seal calls. (Obviously don't use this example key for anything
	// real.) If you want to convert a passphrase to a key, use a suitable
	// package like bcrypt or scrypt.
	secretKeyBytes, err := hex.DecodeString("6368616e676520746869732070617373776f726420746f206120736563726574")
	if err != nil {
		panic(err)
	}

	var secretKey [32]byte
	copy(secretKey[:], secretKeyBytes)

	// You must use a different nonce for each message you encrypt with the
	// same key. Since the nonce here is 192 bits long, a random value
	// provides a sufficiently small probability of repeats.
	var nonce [24]byte
	if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
		panic(err)
	}

	// This encrypts "hello world" and appends the result to the nonce.
	encrypted := secretbox.Seal(nonce[:], []byte("hello world"), &nonce, &secretKey)

	// When you decrypt, you must use the same nonce and key you used to
	// encrypt the message. One way to achieve this is to store the nonce
	// alongside the encrypted message. Above, we stored the nonce in the first
	// 24 bytes of the encrypted text.
	var decryptNonce [24]byte
	copy(decryptNonce[:], encrypted[:24])
	decrypted, ok := secretbox.Open(nil, encrypted[24:], &decryptNonce, &secretKey)
	if !ok {
		panic("decryption error")
	}

	fmt.Println(string(decrypted))
	// Output: hello world
}