// package like bcrypt or scrypt.
	// When decoded the key should be 16 bytes (AES-128) or 32 (AES-256).
	key, _ := hex.DecodeString("6368616e676520746869732070617373776f726420746f206120736563726574")
	plaintext := []byte("exampleplaintext")

	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err.Error())
	}