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: secretbox.go
    path of file: ./repos/go-micro/config/secrets/secretbox
    
    the code of the file until where you have to start completion: // Package secretbox is a config/secrets implementation that uses nacl/secretbox
// to do symmetric encryption / verification
package 
    
func (s *secretBox) Encrypt(in []byte, opts ...secrets.EncryptOption) ([]byte, error) {
	// no opts are expected, so they are ignored

	// there must be a unique nonce for each message
	var nonce [24]byte
	if _, err := rand.Reader.Read(nonce[:]); err != nil {
		return []byte{}, errors.Wrap(err, "couldn't obtain a random nonce from crypto/rand")
	}
	return secretbox.Seal(nonce[:], in, &nonce, &s.secretKey), nil
}