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: token_protector.go
    path of file: ./repos/quic-go/internal/handshake
    
    the code of the file until where you have to start completion: package handshake

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"crypto/sha256"
	"fmt"
	"io"

	"golang.org/x/crypto/hkdf"
)

// TokenProtectorKey is the key used to encrypt both Retry and session resumption tokens.
type Toke
    
func (s *tokenProtectorImpl) NewToken(data []byte) ([]byte, error) {
	var nonce [tokenNonceSize]byte
	if _, err := rand.Read(nonce[:]); err != nil {
		return nil, err
	}
	aead, aeadNonce, err := s.createAEAD(nonce[:])
	if err != nil {
		return nil, err
	}
	return append(nonce[:], aead.Seal(nil, aeadNonce, data, nil)...), nil
}