public function decryptNameId(XMLSecurityKey $key, array $blacklist = []) : void
    {
        if ($this->encryptedNameId === null) {
            /* No NameID to decrypt. */

            return;
        }

        $nameId = Utils::decryptElement($this->encryptedNameId, $key, $blacklist);
        Utils::getContainer()->debugMessage($nameId, 'decrypt');
        $this->nameId = new NameID($nameId);

        $this->encryptedNameId = null;
    }